US 8039597 B2
Antibodies and molecules derived therefrom that bind to 24P4C12 protein and variants thereof, are described wherein 24P4C12 exhibits tissue specific expression in normal adult tissue, and is aberrantly expressed in the cancers listed in Table I. Consequently, 24P4C12 provides a diagnostic, prognostic, prophylactic and/or therapeutic target for cancer. The 24P4C12 gene or fragment thereof, or its encoded protein, or variants thereof, or a fragment thereof, can be used to elicit a humoral or cellular immune response; antibodies or T cells reactive with 24P4C12 can be used in active or passive immunization.
1. An isolated monoclonal antibody or antigen-binding fragment thereof that binds specifically to a 24P4C12 protein comprising the amino acid sequence of SEQ ID NO: 2, wherein the monoclonal antibody comprises the VH region of SEQ ID NO: 123, from residue 1 to 124 and the VL region of SEQ ID NO: 124, from residue 15 to 122.
2. The antibody or fragment of
3. The antibody or fragment of
4. The antibody or fragment of
5. The antibody or fragment of
6. The antibody or fragment of
7. The antibody or fragment of
8. The antibody or fragment of
9. The antibody or fragment of
10. The antibody or fragment of
11. The antibody or fragment of
12. A hybridoma that produces the monoclonal antibody of
13. A pharmaceutical composition that comprises the antibody or fragment of
14. An assay for detecting the presence of a 24P4C12 protein in a biological sample comprising contacting the sample with an antibody of
15. A method of delivering a cytotoxic agent or a diagnostic agent to a cell that expresses a 24P4C12 protein, comprising: providing a cytotoxic agent or a diagnostic agent conjugated to the antibody or fragment of
16. The method of
17. The method of
18. The method of
19. The method of
20. A method for detecting a 24P4C12 protein in a biological sample, comprising steps of: providing the biological sample and a control sample; contacting the biological sample and the control sample with the antibody of
21. The method of
22. A method for reducing 24P4C12 protein expressing tumor growth in a mammal comprising treating the mammal with an effective amount of a combination of the antibody of
23. A method for reducing 24P4C12 protein expressing tumor growth in a mammal comprising treating the mammal with an effective amount of a combination of the antibody of
24. A method for reducing 24P4C12 protein expressing tumor growth in a mammal comprising treating the mammal with an effective amount of a combination of the antibody of
This application claims benefit of provisional application U.S. 61/190,034 filed 7 Sep. 2007. The contents of this application are incorporated herein by reference.
The entire content of the following electronic submission of the sequence listing via the USPTO EFS-WEB server, as authorized and set forth in MPEP §1730 II.B.2(a)(C), is incorporated herein by reference in its entirety for all purposes. The sequence listing is identified on the electronically filed text file as follows:
The invention described herein relates to antibodies, as well as binding fragments thereof and molecules engineered therefrom, that bind proteins, termed 24P4C12. The invention further relates to diagnostic, prognostic, prophylactic and therapeutic methods and compositions useful in the treatment of cancers that express 24P4C12.
Cancer is the second leading cause of human death next to coronary disease. Worldwide, millions of people die from cancer every year. In the United States alone, as reported by the American Cancer Society, cancer causes the death of well over a half-million people annually, with over 1.2 million new cases diagnosed per year. While deaths from heart disease have been declining significantly, those resulting from cancer generally are on the rise. In the early part of the next century, cancer is predicted to become the leading cause of death.
Worldwide, several cancers stand out as the leading killers. In particular, carcinomas of the lung, prostate, breast, colon, pancreas, ovary, and bladder represent the primary causes of cancer death. These and virtually all other carcinomas share a common lethal feature. With very few exceptions, metastatic disease from a carcinoma is fatal. Moreover, even for those cancer patients who initially survive their primary cancers, common experience has shown that their lives are dramatically altered. Many cancer patients experience strong anxieties driven by the awareness of the potential for recurrence or treatment failure. Many cancer patients experience physical debilitations following treatment. Furthermore, many cancer patients experience a recurrence.
Worldwide, prostate cancer is the fourth most prevalent cancer in men. In North America and Northern Europe, it is by far the most common cancer in males and is the second leading cause of cancer death in men. In the United States alone, well over 30,000 men die annually of this disease—second only to lung cancer. Despite the magnitude of these figures, there is still no effective treatment for metastatic prostate cancer. Surgical prostatectomy, radiation therapy, hormone ablation therapy, surgical castration and chemotherapy continue to be the main treatment modalities. Unfortunately, these treatments are ineffective for many and are often associated with undesirable consequences.
On the diagnostic front, the lack of a prostate tumor marker that can accurately detect early-stage, localized tumors remains a significant limitation in the diagnosis and management of this disease. Although the serum prostate specific antigen (PSA) assay has been a very useful tool, however its specificity and general utility is widely regarded as lacking in several important respects.
Progress in identifying additional specific markers for prostate cancer has been improved by the generation of prostate cancer xenografts that can recapitulate different stages of the disease in mice. The LAPC (Los Angeles Prostate Cancer) xenografts are prostate cancer xenografts that have survived passage in severe combined immune deficient (SCID) mice and have exhibited the capacity to mimic the transition from androgen dependence to androgen independence (Klein et al., 1997, Nat. Med. 3:402). More recently identified prostate cancer markers include PCTA-1 (Su et al., 1996, Proc. Natl. Acad. Sci. USA 93: 7252), prostate-specific membrane antigen (PSMA) (Pinto et al., Clin Cancer Res 1996 September 2 (9): 1445-51), STEAP (Hubert, et al., Proc Natl Acad Sci USA. 1999 Dec. 7; 96(25): 14523-8) and prostate stem cell antigen (PSCA) (Reiter et al., 1998, Proc. Natl. Acad. Sci. USA 95: 1735).
While previously identified markers such as PSA, PSMA, PCTA and 24P4C12 have facilitated efforts to diagnose and treat prostate cancer, there is need for the identification of additional markers and therapeutic targets for prostate and related cancers in order to further improve diagnosis and therapy. An estimated 130,200 cases of colorectal cancer occurred in 2000 in the United States, including 93,800 cases of colon cancer and 36,400 of rectal cancer.
Colorectal cancers are the third most common cancers in men and women. Incidence rates declined significantly during 1992-1996 (−2.1% per year). Research suggests that these declines have been due to increased screening and polyp removal, preventing progression of polyps to invasive cancers. There were an estimated 56,300 deaths (47,700 from colon cancer, 8,600 from rectal cancer) in 2000, accounting for about 11% of all U.S. cancer deaths.
At present, surgery is the most common form of therapy for colorectal cancer, and for cancers that have not spread, it is frequently curative. Chemotherapy, or chemotherapy plus radiation, is given before or after surgery to most patients whose cancer has deeply perforated the bowel wall or has spread to the lymph nodes. A permanent colostomy (creation of an abdominal opening for elimination of body wastes) is occasionally needed for colon cancer and is infrequently required for rectal cancer. There continues to be a need for effective diagnostic and treatment modalities for colorectal cancer.
Of all new cases of cancer in the United States, bladder cancer represents approximately 5 percent in men (fifth most common neoplasm) and 3 percent in women (eighth most common neoplasm). The incidence is increasing slowly, concurrent with an increasing older population. In 1998, there was an estimated 54,500 cases, including 39,500 in men and 15,000 in women. The age-adjusted incidence in the United States is 32 per 100,000 for men and eight per 100,000 in women. The historic male/female ratio of 3:1 may be decreasing related to smoking patterns in women. There were an estimated 11,000 deaths from bladder cancer in 1998 (7,800 in men and 3,900 in women). Bladder cancer incidence and mortality strongly increase with age and will be an increasing problem as the population becomes more elderly.
Most bladder cancers recur in the bladder. Bladder cancer is managed with a combination of transurethral resection of the bladder (TUR) and intravesical chemotherapy or immunotherapy. The multifocal and recurrent nature of bladder cancer points out the limitations of TUR. Most muscle-invasive cancers are not cured by TUR alone. Radical cystectomy and urinary diversion is the most effective means to eliminate the cancer but carry an undeniable impact on urinary and sexual function. There continues to be a significant need for treatment modalities that are beneficial for bladder cancer patients.
There were an estimated 164,100 new cases of lung and bronchial cancer in 2000, accounting for 14% of all U.S. cancer diagnoses. The incidence rate of lung and bronchial cancer is declining significantly in men, from a high of 86.5 per 100,000 in 1984 to 70.0 in 1996. In the 1990s, the rate of increase among women began to slow. In 1996, the incidence rate in women was 42.3 per 100,000.
Lung and bronchial cancer caused an estimated 156,900 deaths in 2000, accounting for 28% of all cancer deaths. During 1992-1996, mortality from lung cancer declined significantly among men (−1.7% per year) while rates for women were still significantly increasing (0.9% per year). Since 1987, more women have died each year of lung cancer than breast cancer, which, for over 40 years, was the major cause of cancer death in women. Decreasing lung cancer incidence and mortality rates most likely resulted from decreased smoking rates over the previous 30 years; however, decreasing smoking patterns among women lag behind those of men. Of concern, although the declines in adult tobacco use have slowed, tobacco use in youth is increasing again.
Treatment options for lung and bronchial cancer are determined by the type and stage of the cancer and include surgery, radiation therapy, and chemotherapy. For many localized cancers, surgery is usually the treatment of choice. Because the disease has usually spread by the time it is discovered, radiation therapy and chemotherapy are often needed in combination with surgery. Chemotherapy alone or combined with radiation is the treatment of choice for small cell lung cancer; on this regimen, a large percentage of patients experience remission, which in some cases is long lasting. There is however, an ongoing need for effective treatment and diagnostic approaches for lung and bronchial cancers.
An estimated 182,800 new invasive cases of breast cancer were expected to occur among women in the United States during 2000. Additionally, about 1,400 new cases of breast cancer were expected to be diagnosed in men in 2000. After increasing about 4% per year in the 1980s, breast cancer incidence rates in women have leveled off in the 1990s to about 110.6 cases per 100,000.
In the U.S. alone, there were an estimated 41,200 deaths (40,800 women, 400 men) in 2000 due to breast cancer. Breast cancer ranks second among cancer deaths in women. According to the most recent data, mortality rates declined significantly during 1992-1996 with the largest decreases in younger women, both white and black. These decreases were probably the result of earlier detection and improved treatment.
Taking into account the medical circumstances and the patient's preferences, treatment of breast cancer may involve lumpectomy (local removal of the tumor) and removal of the lymph nodes under the arm; mastectomy (surgical removal of the breast) and removal of the lymph nodes under the arm; radiation therapy; chemotherapy; or hormone therapy. Often, two or more methods are used in combination. Numerous studies have shown that, for early stage disease, long-term survival rates after lumpectomy plus radiotherapy are similar to survival rates after modified radical mastectomy. Significant advances in reconstruction techniques provide several options for breast reconstruction after mastectomy. Recently, such reconstruction has been done at the same time as the mastectomy.
Local excision of ductal carcinoma in situ (DCIS) with adequate amounts of surrounding normal breast tissue may prevent the local recurrence of the DCIS. Radiation to the breast and/or tamoxifen may reduce the chance of DCIS occurring in the remaining breast tissue. This is important because DCIS, if left untreated, may develop into invasive breast cancer. Nevertheless, there are serious side effects or sequelae to these treatments. There is, therefore, a need for efficacious breast cancer treatments.
There were an estimated 23,100 new cases of ovarian cancer in the United States in 2000. It accounts for 4% of all cancers among women and ranks second among gynecologic cancers. During 1992-1996, ovarian cancer incidence rates were significantly declining. Consequent to ovarian cancer, there were an estimated 14,000 deaths in 2000. Ovarian cancer causes more deaths than any other cancer of the female reproductive system.
Surgery, radiation therapy, and chemotherapy are treatment options for ovarian cancer. Surgery usually includes the removal of one or both ovaries, the fallopian tubes (salpingo-oophorectomy), and the uterus (hysterectomy). In some very early tumors, only the involved ovary will be removed, especially in young women who wish to have children. In advanced disease, an attempt is made to remove all intra-abdominal disease to enhance the effect of chemotherapy. There continues to be an important need for effective treatment options for ovarian cancer.
There were an estimated 28,300 new cases of pancreatic cancer in the United States in 2000. Over the past 20 years, rates of pancreatic cancer have declined in men. Rates among women have remained approximately constant but may be beginning to decline. Pancreatic cancer caused an estimated 28,200 deaths in 2000 in the United States. Over the past 20 years, there has been a slight but significant decrease in mortality rates among men (about −0.9% per year) while rates have increased slightly among women.
Surgery, radiation therapy, and chemotherapy are treatment options for pancreatic cancer. These treatment options can extend survival and/or relieve symptoms in many patients but are not likely to produce a cure for most. There is a significant need for additional therapeutic and diagnostic options for cancers. These include the use of antibodies, vaccines, and small molecules as treatment modalities. Additionally, there is also a need to use these modilities as research tools to diagnose, detect, monitor, and further the state of the art in all areas of cancer treatment and studies.
The therapeutic utility of monoclonal antibodies (mAbs) (G. Kohler and C. Milstein, Nature 256:495-497 (1975)) is being realized. Monoclonal antibodies have now been approved as therapies in transplantation, cancer, infectious disease, cardiovascular disease and inflammation. Different isotypes have different effector functions. Such differences in function are reflected in distinct 3-dimensional structures for the various immunoglobulin isotypes (P. M. Alzari et al., Annual Rev. Immunol., 6:555-580 (1988)).
Because mice are convenient for immunization and recognize most human antigens as foreign, mAbs against human targets with therapeutic potential have typically been of murine origin. However, murine mAbs have inherent disadvantages as human therapeutics. They require more frequent dosing as mAbs have a shorter circulating half-life in humans than human antibodies. More critically, the repeated administration of murine antibodies to the human immune system causes the human immune system to respond by recognizing the mouse protein as a foreign and generating a human anti-mouse antibody (HAMA) response. Such a HAMA response may result in allergic reaction and the rapid clearing of the murine antibody from the system thereby rendering the treatment by murine antibody useless. To avoid such affects, attempts to create human immune systems within mice have been attempted.
Initial attempts hoped to create transgenic mice capable of responding to antigens with antibodies having human sequences (See Bruggemann et al., Proc. Nat'l. Acad. Sci. USA 86:6709-6713 (1989)), but were limited by the amount of DNA that could be stably maintained by available cloning vehicles. The use of yeast artificial chromosome (YAC) cloning vectors led the way to introducing large germline fragments of human Ig locus into transgenic mammals. Essentially a majority of the human V, D, and J region genes arranged with the same spacing found in the human genome and the human constant regions were introduced into mice using YACs. One such transgenic mouse strain is known as XenoMouse® mice and is commercially available from Amgen Fremont, Inc. (Fremont Calif.).
The invention provides antibodies as well as binding fragments thereof and molecules engineered therefrom, that bind to 24P4C12 proteins and polypeptide fragments of 24P4C12 proteins. The invention comprises polyclonal and monoclonal antibodies, murine and other mammalian antibodies, chimeric antibodies, humanized and fully human antibodies, and antibodies labeled with a detectable marker or therapeutic agent. In certain embodiments, there is a proviso that the entire nucleic acid sequence of
The invention further provides methods for detecting the presence and status of 24P4C12 polynucleotides and proteins in various biological samples, as well as methods for identifying cells that express 24P4C12. An embodiment of this invention provides methods for monitoring 24P4C12 gene products in a tissue or hematology sample having or suspected of having some form of growth dysregulation such as cancer.
The invention further provides various immunogenic or therapeutic compositions and strategies for treating cancers that express 24P4C12 such as cancers of tissues listed in Table I, including therapies aimed at inhibiting the transcription, translation, processing or function of 24P4C12 as well as cancer vaccines. In one aspect, the invention provides compositions, and methods comprising them, for treating a cancer that expresses 24P4C12 in a human subject wherein the composition comprises a carrier suitable for human use and a human unit dose of one or more than one agent that inhibits the production or function of 24P4C12. Preferably, the carrier is a uniquely human carrier. In another aspect of the invention, the agent is a moiety that is immunoreactive with 24P4C12 protein. Non-limiting examples of such moieties include, but are not limited to, antibodies (such as single chain, monoclonal, polyclonal, humanized, chimeric, or human antibodies), functional equivalents thereof (whether naturally occurring or synthetic), and combinations thereof. The antibodies can be conjugated to a diagnostic or therapeutic moiety. In another aspect, the agent is a small molecule as defined herein.
FIG. 2AA The cDNA and amino acid sequence of Ha5-7be37.1 VH. Underlined is a portion of the light chain constant region.
FIG. 2AB The cDNA and amino acid sequence of Ha5-7be37.1 VL. Underlined is a portion of the light chain constant region. Double underline is the leader sequence.
FIG. 2AC The cDNA and amino acid sequence of Ha5-7acd16.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 2AD The cDNA and amino acid sequence of Ha5-7acd16.1 VL. Underlined is a portion of the light chain constant region. Double underline is the leader sequence.
FIG. 2AE The cDNA and amino acid sequence of Ha5-7acd7.1.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 2AF The cDNA and amino acid sequence of Ha5-7acd7.1.1 VL. Double-underlined is the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 2AG The cDNA and amino acid sequence of Ha5-7be20.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 2AH The cDNA and amino acid sequence of Ha5-7be20.1 VL. Double-underlined is the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 2AI The cDNA and amino acid sequence of Ha5-7acd5.1.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 2AJ The cDNA and amino acid sequence of Ha5-7acd5.1.1 VL. Underlined is a portion of the light chain constant region. Double underline is the leader sequence.
FIG. 2AK The cDNA and amino acid sequence of Ha5-7be34.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 2AL The cDNA and amino acid sequence of Ha5-7be34.1 VL. Underlined is a portion of the light chain constant region. Double underline is the leader sequence.
FIG. 2AM The cDNA and amino acid sequence of Ha5-7acd3.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 2AN The cDNA and amino acid sequence of Ha5-7acd3.1 VL. Double-underlined is part of the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 2AO The cDNA and amino acid sequence of Ha5-7acd2.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 2AP The cDNA and amino acid sequence of Ha5-7acd2.1 VL. Double-underlined is part of the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 2AQ The cDNA and amino acid sequence of Ha5-8ac4.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 2AR The cDNA and amino acid sequence of Ha5-8ac4.1 VL. Underlined is a portion of the light chain constant region.
FIG. 2AS The cDNA and amino acid sequence of Ha5-4(2,5)31.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 2AT The cDNA and amino acid sequence of Ha5-4(2,5)31.1 VL. Double-underlined is part of the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 2AU The cDNA and amino acid sequence of Ha5-11a1.1.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 2AV The cDNA and amino acid sequence of Ha5-11a1.1.1 VL. Underlined is a portion of the heavy chain constant region. Double underline is the leader sequence.
FIG. 2AW The cDNA and amino acid sequence of Ha5-11b1.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 2AX The cDNA and amino acid sequence of Ha5-11b1.1 VL. Double-underlined is part of the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 2AY The cDNA and amino acid sequence of Ha5-7be7.1 VH. Double-underlined is part of the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 3AA The amino acid sequence of Ha5-7be37.1 VH.
FIG. 3AB The amino acid sequence of Ha5-7be37.1 VL. Underlined is a portion of the light chain constant region.
FIG. 3AC The amino acid sequence of Ha5-7acd16.1 VH.
FIG. 3AD The amino acid sequence of Ha5-7acd16.1 VL. Underlined is a portion of the light chain constant region.
FIG. 3AE The amino acid sequence of Ha5-7acd7.1.1 VH. Double-underlined is the leader sequence. Underlined is a portion of the light chain constant region.
FIG. 3AF The amino acid sequence of Ha5-7acd7.1.1 VL. Double-underlined is the leader sequence. Underlined is a portion of the light chain constant region.
FIG. 3AG The amino acid sequence of Ha5-7be20.1 VH. Double-underlined is the leader sequence. Underlined is a portion of the light chain constant region.
FIG. 3AH The amino acid sequence of Ha5-7be20.1 VL. Double-underlined is part of the leader sequence. Underlined is a portion of the light chain constant region.
FIG. 3AI The amino acid sequence of Ha5-7acd5.1.1 VH. Double-underlined is part of the leader sequence, and underlined is a portion of the heavy chain constant region.
FIG. 3AJ The amino acid sequence of Ha5-7acd5.1.1 VL. Underlined is a portion of the light chain constant region.
FIG. 3AK The amino acid sequence of Ha5-7be34.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 3AL The amino acid sequence of Ha5-7be34.1 VL. Underlined is a portion of the light chain constant region.
FIG. 3AM The amino acid sequence of Ha5-7acd3.1 VH. Double-underlined is the leader sequence, and underlined is a portion of the heavy chain constant region.
FIG. 3AN The amino acid sequence of Ha5-7acd3.1 VL. Double-underlined is part of the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 3AO The amino acid sequence of Ha5-7acd2.1 VH. Double-underlined is the leader sequence, and underlined is a portion of the heavy chain constant region.
FIG. 3AP The amino acid sequence of Ha5-7acd2.1 VL. Double-underlined is part of the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 3AQ The amino acid sequence of Ha5-8ac4.1 VH. Double-underlined is the leader sequence, and underlined is a portion of the heavy chain constant region.
FIG. 3AR The amino acid sequence of Ha5-8ac4.1 VL. Double-underlined is part of the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 3AS The amino acid sequence of Ha5-4(2,5)31.1 VH. Double-underlined is the leader sequence, and underlined is a portion of the heavy chain constant region.
FIG. 3AT The amino acid sequence of Ha5-4(2,5)31.1 VL. Double-underlined is part of the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 3AU The amino acid sequence of Ha5-11a1.1.1 VH. Double-underlined is part of the leader sequence, and underlined is a portion of the heavy chain constant region.
FIG. 3AV The amino acid sequence of Ha5-11a1.1.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 3AW The amino acid sequence of Ha5-11b1.1 VH. Underlined is a portion of the heavy chain constant region.
FIG. 3AX The amino acid sequence of Ha5-11b1.1 VL. Double-underlined is part of the leader sequence, and underlined is a portion of the light chain constant region.
FIG. 3AY The amino acid sequence of Ha5-7be7.1 VH. Underlined is a portion of the light chain constant region.
FIG. 4AA Alignment of Ha5-7be37.1 VH (a portion of SEQ ID NOS:71-72) to human Ig germline.
FIG. 4AB Alignment of Ha5-7be37.1 VL (a portion of SEQ ID NOS:73-74) to human Ig germline.
FIG. 4AC Alignment of Ha5-7acd16.1 VH (a portion of SEQ ID NOS:75-76) to human Ig germline.
FIG. 4AD Alignment of Ha5-7acd16.1 VL (a portion of SEQ ID NOS:77-78) to human Ig germline.
FIG. 4AE Alignment of Ha5-7acd7.1.1 VH (a portion of SEQ ID NOS:79-80) to human Ig germline.
FIG. 4AF Alignment of Ha5-7acd7.1.1 VL (a portion of SEQ ID NOS:81-82) to human Ig germline.
FIG. 4AG Alignment of Ha5-7be20.1 VH (a portion of SEQ ID NOS:83-84) to human Ig germline.
FIG. 4AH Alignment of Ha5-7be20.1 VL (a portion of SEQ ID NOS:85-86) to human Ig germline.
FIG. 4AI Alignment of Ha5-7acd5.1.1 VH (a portion of SEQ ID NOS:87-88) to human Ig germline.
FIG. 4AJ Alignment of Ha5-7acd5.1.1 VL (a portion of SEQ ID NOS:89-90) to human Ig germline.
FIG. 4AK Alignment of Ha5-7be34.1 VH (a portion of SEQ ID NOS:91-92) to human Ig germline.
FIG. 4AL Alignment of Ha5-7be34.1 VL (a portion of SEQ ID NOS:93-94) to human Ig germline.
FIG. 4AM Alignment of Ha5-7acd3.1 VH (a portion of SEQ ID NOS:95-96) to human Ig germline.
FIG. 4AN Alignment of Ha5-7acd3.1 VL (a portion of SEQ ID NOS:97-98) to human Ig germline.
FIG. 4AO Alignment of Ha5-7acd2.1 VH (a portion of SEQ ID NOS:99-100) to human Ig germline.
FIG. 4AP Alignment of Ha5-7acd2.1 VL (a portion of SEQ ID NOS: 101-102) to human Ig germline.
FIG. 4AQ Alignment of Ha5-8acd4.1 VH (a portion of SEQ ID NOS:103-104) to human Ig germline.
FIG. 4AR Alignment of Ha5-8acd4.1 VL (a portion of SEQ ID NOS:105-106) to human Ig germline.
FIG. 4AS Alignment of Ha5-4(2,5)31.1 VH (a portion of SEQ ID NOS:107-108) to human Ig germline.
FIG. 4AT Alignment of Ha5-4(2,5)31.1 VL (a portion of SEQ ID NOS:109-110) to human Ig germline.
FIG. 4AU Alignment of Ha5-11a1.1.1 VH (a portion of SEQ ID NOS:111-112) to human Ig germline.
FIG. 4AV Alignment of Ha5-11a1.1.1 VL (a portion of SEQ ID NOS:113-114) to human Ig germline.
FIG. 4AW Alignment of Ha5-11b1.1 VH (a portion of SEQ ID NOS:115-116) to human Ig germline.
FIG. 4AX Alignment of Ha5-11b1.1 VL (a portion of SEQ ID NOS:117-118) to human Ig germline.
FIG. 4AY Alignment of Ha5-7be7.1 VH (a portion of SEQ ID NOS:119-120) to human Ig germline.
II.) 24P4C12 Polynucleotides
II.A.) Uses of 24P4C12 Polynucleotides
III.A.) Motif-bearing Protein Embodiments
III.B.) Expression of 24P4C12-related Proteins
III.C.) Modifications of 24P4C12-related Proteins
III.D.) Uses of 24P4C12-related Proteins
IV.) 24P4C12 Antibodies
V.) 24P4C12 Cellular Immune Responses
VI.) 24P4C12 Transgenic Animals
VII.) Methods for the Detection of 24P4C12
VIII.) Methods for Monitoring the Status of 24P4C12-related Genes and Their Products
IX.) Identification of Molecules That Interact With 24P4C12
X.) Therapeutic Methods and Compositions
X.A.) Anti-Cancer Vaccines
X.B.) 24P4C12 as a Target for Antibody-Based Therapy
X.C.) 24P4C12 as a Target for Cellular Immune Responses
X.D.) Adoptive Immunotherapy
X.E.) Administration of Vaccines for Therapeutic or Prophylactic Purposes
XI.) Diagnostic and Prognostic Embodiments of 24P4C12.
XII.) Inhibition of 24P4C12 Protein Function
XII.A.) Inhibition of 24P4C12 With Intracellular Antibodies
XII.B.) Inhibition of 24P4C12 with Recombinant Proteins
XII.C.) Inhibition of 24P4C12 Transcription or Translation
XII.D.) General Considerations for Therapeutic Strategies
XIII.) Identification, Characterization and Use of Modulators of 24P4C12
XIV.) RNAi and Therapeutic use of small interfering RNA (siRNAs)
XV.) KITS/Articles of Manufacture
Unless otherwise defined, all terms of art, notations and other scientific terms or terminology used herein are intended to have the meanings commonly understood by those of skill in the art to which this invention pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and/or for ready reference, and the inclusion of such definitions herein should not necessarily be construed to represent a substantial difference over what is generally understood in the art. Many of the techniques and procedures described or referenced herein are well understood and commonly employed using conventional methodology by those skilled in the art, such as, for example, the widely utilized molecular cloning methodologies described in Sambrook et al., Molecular Cloning: A Laboratory Manual 2nd. edition (1989) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. As appropriate, procedures involving the use of commercially available kits and reagents are generally carried out in accordance with manufacturer defined protocols and/or parameters unless otherwise noted.
The terms “advanced cancer”, “locally advanced cancer”, “advanced disease” and “locally advanced disease” mean cancers that have extended through the relevant tissue capsule, and are meant to include stage C disease under the American Urological Association (AUA) system, stage C1-C2 disease under the Whitmore-Jewett system, and stage T3-T4 and N+ disease under the TNM (tumor, node, metastasis) system. In general, surgery is not recommended for patients with locally advanced disease, and these patients have substantially less favorable outcomes compared to patients having clinically localized (organ-confined) cancer.
“Altering the native glycosylation pattern” is intended for purposes herein to mean deleting one or more carbohydrate moieties found in native sequence 24P4C12 (either by removing the underlying glycosylation site or by deleting the glycosylation by chemical and/or enzymatic means), and/or adding one or more glycosylation sites that are not present in the native sequence 24P4C12. In addition, the phrase includes qualitative changes in the glycosylation of the native proteins, involving a change in the nature and proportions of the various carbohydrate moieties present.
The term “analog” refers to a molecule which is structurally similar or shares similar or corresponding attributes with another molecule (e.g. a 24P4C12-related protein). For example, an analog of a 24P4C12 protein can be specifically bound by an antibody or T cell that specifically binds to 24P4C12.
The term “antibody” is used in the broadest sense unless clearly indicated otherwise. Therefore, an “antibody” can be naturally occurring or man-made such as monoclonal antibodies produced by conventional hybridoma technology. Anti-24P4C12 antibodies comprise monoclonal and polyclonal antibodies as well as fragments containing the antigen-binding domain and/or one or more complementarity determining regions of these antibodies. As used herein, the term “antibody” refers to any form of antibody or fragment thereof that specifically binds 24P4C12 and/or exhibits the desired biological activity and specifically covers monoclonal antibodies (including full length monoclonal antibodies), polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies), and antibody fragments so long as they specifically bind 24P4C12 and/or exhibit the desired biological activity. Any specific antibody can be used in the methods and compositions provided herein. Thus, in one embodiment the term “antibody” encompasses a molecule comprising at least one variable region from a light chain immunoglobulin molecule and at least one variable region from a heavy chain molecule that in combination form a specific binding site for the target antigen. In one embodiment, the antibody is an IgG antibody. For example, the antibody is a IgG1, IgG2, IgG3, or IgG4 antibody. The antibodies useful in the present methods and compositions can be generated in cell culture, in phage, or in various animals, including but not limited to cows, rabbits, goats, mice, rats, hamsters, guinea pigs, sheep, dogs, cats, monkeys, chimpanzees, apes. Therefore, in one embodiment, an antibody of the present invention is a mammalian antibody. Phage techniques can be used to isolate an initial antibody or to generate variants with altered specificity or avidity characteristics. Such techniques are routine and well known in the art. In one embodiment, the antibody is produced by recombinant means known in the art. For example, a recombinant antibody can be produced by transfecting a host cell with a vector comprising a DNA sequence encoding the antibody. One or more vectors can be used to transfect the DNA sequence expressing at least one VL and one VH region in the host cell. Exemplary descriptions of recombinant means of antibody generation and production include Delves, ANTIBODY PRODUCTION: ESSENTIAL TECHNIQUES (Wiley, 1997); Shephard, et al., MONOCLONAL ANTIBODIES (Oxford University Press, 2000); Goding, MONOCLONAL ANTIBODIES: PRINCIPLES AND PRACTICE (Academic Press, 1993); CURRENT PROTOCOLS IN IMMUNOLOGY (John Wiley & Sons, most recent edition). An antibody of the present invention can be modified by recombinant means to increase greater efficacy of the antibody in mediating the desired function. Thus, it is within the scope of the invention that antibodies can be modified by substitutions using recombinant means. Typically, the substitutions will be conservative substitutions. For example, at least one amino acid in the constant region of the antibody can be replaced with a different residue. See, e.g., U.S. Pat. No. 5,624,821, U.S. Pat. No. 6,194,551, Application No. WO 9958572; and Angal, et al., Mol. Immunol. 30: 105-08 (1993). The modification in amino acids includes deletions, additions, and substitutions of amino acids. In some cases, such changes are made to reduce undesired activities, e.g., complement-dependent cytotoxicity. Frequently, the antibodies are labeled by joining, either covalently or non-covalently, a substance which provides for a detectable signal. A wide variety of labels and conjugation techniques are known and are reported extensively in both the scientific and patent literature. These antibodies can be screened for binding to normal or defective 24P4C12. See e.g., ANTIBODY ENGINEERING: A PRACTICAL APPROACH (Oxford University Press, 1996). Suitable antibodies with the desired biologic activities can be identified the following in vitro assays including but not limited to: proliferation, migration, adhesion, soft agar growth, angiogenesis, cell-cell communication, apoptosis, transport, signal transduction, and the following in vivo assays such as the inhibition of tumor growth. The antibodies provided herein can also be useful in diagnostic applications. As capture or non-neutralizing antibodies, they can be screened for the ability to bind to the specific antigen without inhibiting the receptor-binding or biological activity of the antigen. As neutralizing antibodies, the antibodies can be useful in competitive binding assays. They can also be used to quantify the 24P4C12 or its receptor.
The term “antigen-binding portion” or “antibody fragment” of an antibody (or simply “antibody portion”), as used herein, refers to one or more fragments of a 24P4C12 antibody that retain the ability to specifically bind to an antigen (e.g., 24P4C12 and variants;
As used herein, any form of the “antigen” can be used to generate an antibody that is specific for 24P4C12. Thus, the eliciting antigen may be a single epitope, multiple epitopes, or the entire protein alone or in combination with one or more immunogenicity enhancing agents known in the art. The eliciting antigen may be an isolated full-length protein, a cell surface protein (e.g., immunizing with cells transfected with at least a portion of the antigen), or a soluble protein (e.g., immunizing with only the extracellular domain portion of the protein). The antigen may be produced in a genetically modified cell. The DNA encoding the antigen may be genomic or non-genomic (e.g., cDNA) and encodes at least a portion of the extracellular domain. As used herein, the term “portion” refers to the minimal number of amino acids or nucleic acids, as appropriate, to constitute an immunogenic epitope of the antigen of interest. Any genetic vectors suitable for transformation of the cells of interest may be employed, including but not limited to adenoviral vectors, plasmids, and non-viral vectors, such as cationic lipids. In one embodiment, the antibody of the methods and compositions herein specifically bind at least a portion of the extracellular domain of the 24P4C12 of interest.
The antibodies or antigen binding fragments thereof provided herein may be conjugated to a “bioactive agent.” As used herein, the term “bioactive agent” refers to any synthetic or naturally occurring compound that binds the antigen and/or enhances or mediates a desired biological effect to enhance cell-killing toxins.
In one embodiment, the binding fragments useful in the present invention are biologically active fragments. As used herein, the term “biologically active” refers to an antibody or antibody fragment that is capable of binding the desired antigenic epitope and directly or indirectly exerting a biologic effect. Direct effects include, but are not limited to the modulation, stimulation, and/or inhibition of a growth signal, the modulation, stimulation, and/or inhibition of an anti-apoptotic signal, the modulation, stimulation, and/or inhibition of an apoptotic or necrotic signal, modulation, stimulation, and/or inhibition the ADCC cascade, and modulation, stimulation, and/or inhibition the CDC cascade.
“Bispecific” antibodies are also useful in the present methods and compositions. As used herein, the term “bispecific antibody” refers to an antibody, typically a monoclonal antibody, having binding specificities for at least two different antigenic epitopes. In one embodiment, the epitopes are from the same antigen. In another embodiment, the epitopes are from two different antigens. Methods for making bispecific antibodies are known in the art. For example, bispecific antibodies can be produced recombinantly using the co-expression of two immunoglobulin heavy chain/light chain pairs. See, e.g., Milstein et al., Nature 305:537-39 (1983). Alternatively, bispecific antibodies can be prepared using chemical linkage. See, e.g., Brennan, et al., Science 229:81 (1985). Bispecific antibodies include bispecific antibody fragments. See, e.g., Hollinger, et al., Proc. Natl. Acad. Sci. U.S.A. 90:6444-48 (1993), Gruber, et al., J. Immunol. 152:5368 (1994).
The monoclonal antibodies herein specifically include “chimeric” antibodies in which a portion of the heavy and/or light chain is identical with or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular antibody class or subclass, while the remainder of the chain(s) is identical with or homologous to corresponding sequences in antibodies derived from another species or belonging to another antibody class or subclass, as well as fragments of such antibodies, so long as they specifically bind the target antigen and/or exhibit the desired biological activity (U.S. Pat. No. 4,816,567; and Morrison et al., Proc. Natl. Acad. Sci. USA 81: 6851-6855 (1984)).
The term “Chemotherapeutic Agent” refers to all chemical compounds that are effective in inhibiting tumor growth. Non-limiting examples of chemotherapeutic agents include alkylating agents; for example, nitrogen mustards, ethyleneimine compounds and alkyl sulphonates; antimetabolites; for example, folic acid, purine or pyrimidine antagonists; mitotic inhibitors; for example, vinca alkaloids and derivatives of podophyllotoxin, cytotoxic antibiotics, compounds that damage or interfere with DNA expression, and growth factor receptor antagonists. In addition, chemotherapeutic agents include cytotoxic agents (as defined herein), antibodies, biological molecules and small molecules.
The term “codon optimized sequences” refers to nucleotide sequences that have been optimized for a particular host species by replacing any codons having a usage frequency of less than about 20%. Nucleotide sequences that have been optimized for expression in a given host species by elimination of spurious polyadenylation sequences, elimination of exon/intron splicing signals, elimination of transposon-like repeats and/or optimization of GC content in addition to codon optimization are referred to herein as an “expression enhanced sequences.”
A “combinatorial library” is a collection of diverse chemical compounds generated by either chemical synthesis or biological synthesis by combining a number of chemical “building blocks” such as reagents. For example, a linear combinatorial chemical library, such as a polypeptide (e.g., mutein) library, is formed by combining a set of chemical building blocks called amino acids in every possible way for a given compound length (i.e., the number of amino acids in a polypeptide compound). Numerous chemical compounds are synthesized through such combinatorial mixing of chemical building blocks (Gallop et al., J. Med. Chem. 37(9): 1233-1251 (1994)).
Preparation and screening of combinatorial libraries is well known to those of skill in the art. Such combinatorial chemical libraries include, but are not limited to, peptide libraries (see, e.g., U.S. Pat. No. 5,010,175, Furka, Pept. Prot. Res. 37:487-493 (1991), Houghton et al., Nature, 354:84-88 (1991)), peptoids (PCT Publication No WO 91/19735), encoded peptides (PCT Publication WO 93/20242), random bio-oligomers (PCT Publication WO 92/00091), benzodiazepines (U.S. Pat. No. 5,288,514), diversomers such as hydantoins, benzodiazepines and dipeptides (Hobbs et al., Proc. Nat. Acad. Sci. USA 90:6909-6913 (1993)), vinylogous polypeptides (Hagihara et al., J. Amer. Chem. Soc. 114:6568 (1992)), nonpeptidal peptidomimetics with a Beta-D-Glucose scaffolding (Hirschmann et al., J. Amer. Chem. Soc. 114:9217-9218 (1992)), analogous organic syntheses of small compound libraries (Chen et al., J. Amer. Chem. Soc. 116:2661 (1994)), oligocarbamates (Cho, et al., Science 261:1303 (1993)), and/or peptidyl phosphonates (Campbell et al., J. Org. Chem. 59:658 (1994)). See, generally, Gordon et al., J. Med. Chem. 37:1385 (1994), nucleic acid libraries (see, e.g., Stratagene, Corp.), peptide nucleic acid libraries (see, e.g., U.S. Pat. No. 5,539,083), antibody libraries (see, e.g., Vaughn et al., Nature Biotechnology 14(3): 309-314 (1996), and PCT/US96/10287), carbohydrate libraries (see, e.g., Liang et al., Science 274:1520-1522 (1996), and U.S. Pat. No. 5,593,853), and small organic molecule libraries (see, e.g., benzodiazepines, Baum, C&EN, Jan. 18, page 33 (1993); isoprenoids, U.S. Pat. No. 5,569,588; thiazolidinones and metathiazanones, U.S. Pat. No. 5,549,974; pyrrolidines, U.S. Pat. Nos. 5,525,735 and 5,519,134; morpholino compounds, U.S. Pat. No. 5,506,337; benzodiazepines, U.S. Pat. No. 5,288,514; and the like).
Devices for the preparation of combinatorial libraries are commercially available (see, e.g., 357 NIPS, 390 NIPS, Advanced Chem Tech, Louisville Ky.; Symphony, Rainin, Woburn, Mass.; 433A, Applied Biosystems, Foster City, Calif.; 9050, Plus, Millipore, Bedford, NIA). A number of well-known robotic systems have also been developed for solution phase chemistries. These systems include automated workstations such as the automated synthesis apparatus developed by Takeda Chemical Industries, LTD. (Osaka, Japan) and many robotic systems utilizing robotic arms (Zymate H, Zymark Corporation, Hopkinton, Mass.; Orca, Hewlett-Packard, Palo Alto, Calif.), which mimic the manual synthetic operations performed by a chemist. Any of the above devices are suitable for use with the present invention. The nature and implementation of modifications to these devices (if any) so that they can operate as discussed herein will be apparent to persons skilled in the relevant art. In addition, numerous combinatorial libraries are themselves commercially available (see, e.g., ComGenex, Princeton, N.J.; Asinex, Moscow, RU; Tripos, Inc., St. Louis, Mo.; ChemStar, Ltd, Moscow, RU; 3D Pharmaceuticals, Exton, Pa.; Martek Biosciences, Columbia, Md.; etc.).
As used herein, the term “conservative substitution” refers to substitutions of amino acids are known to those of skill in this art and may be made generally without altering the biological activity of the resulting molecule. Those of skill in this art recognize that, in general, single amino acid substitutions in non-essential regions of a polypeptide do not substantially alter biological activity (see, e.g., Watson, et al., MOLECULAR BIOLOGY OF THE GENE, The Benjamin/Cummings Pub. Co., p. 224 (4th Edition 1987)). Such exemplary substitutions are preferably made in accordance with those set forth in Table(s) III(a-b). For example, such changes include substituting any of isoleucine (I), valine (V), and leucine (L) for any other of these hydrophobic amino acids; aspartic acid (D) for glutamic acid (E) and vice versa; glutamine (O) for asparagine (N) and vice versa; and serine (S) for threonine (T) and vice versa. Other substitutions can also be considered conservative, depending on the environment of the particular amino acid and its role in the three-dimensional structure of the protein. For example, glycine (G) and alanine (A) can frequently be interchangeable, as can alanine (A) and valine (V). Methionine (M), which is relatively hydrophobic, can frequently be interchanged with leucine and isoleucine, and sometimes with valine. Lysine (K) and arginine (R) are frequently interchangeable in locations in which the significant feature of the amino acid residue is its charge and the differing pK's of these two amino acid residues are not significant. Still other changes can be considered “conservative” in particular environments (see, e.g. Table III(a) herein; pages 13-15 “Biochemistry” 2nd ED. Lubert Stryer ed (Stanford University); Henikoff et al., PNAS1992 Vol 89 10915-10919; Lei et al., J Biol Chem 1995 May 19; 270(20):11882-6). Other substitutions are also permissible and may be determined empirically or in accord with known conservative substitutions.
The term “cytotoxic agent” refers to a substance that inhibits or prevents the expression activity of cells, function of cells and/or causes destruction of cells. The term is intended to include radioactive isotopes, chemotherapeutic agents, and toxins such as small molecule toxins or enzymatically active toxins of bacterial, fungal, plant or animal origin, including fragments and/or variants thereof. Examples of cytotoxic agents include, but are not limited to auristatins, auristatin e, auristatin f, auromycins, maytansinoids, yttrium, bismuth, ricin, ricin A-chain, combrestatin, duocarmycins, dolostatins, doxorubicin, daunorubicin, taxol, cisplatin, cc1065, ethidium bromide, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicine, dihydroxy anthracin dione, actinomycin, diphtheria toxin, Pseudomonas exotoxin (PE) A, PE40, abrin, abrin A chain, modeccin A chain, alpha-sarcin, gelonin, mitogellin, retstrictocin, phenomycin, enomycin, curicin, crotin, calicheamicin, Sapaonaria officinalis inhibitor, and glucocorticoid and other chemotherapeutic agents, as well as radioisotopes such as At211, I131, I125, Y90, Re186, Re188, Sm153, Bi212 or 213, P32 and radioactive isotopes of Lu including Lu177. Antibodies may also be conjugated to an anti-cancer pro-drug activating enzyme capable of converting the pro-drug to its active form.
As used herein, the term “diabodies” refers to small antibody fragments with two antigen-binding sites, which fragments comprise a heavy chain variable domain (VH) connected to a light chain variable domain (VL) in the same polypeptide chain (VH-VL). By using a linker that is too short to allow pairing between the two domains on the same chain, the domains are forced to pair with the complementary domains of another chain and create two antigen-binding sites. Diabodies are described more fully in, e.g., EP 404,097; WO 93/11161; and Hollinger et al., Proc. Natl. Acad. Sci. USA 90:6444-48 (1993).
The “gene product” is used herein to indicate a peptide/protein or mRNA. For example, a “gene product of the invention” is sometimes referred to herein as a “cancer amino acid sequence”, “cancer protein”, “protein of a cancer listed in Table I”, a “cancer mRNA”, “mRNA of a cancer listed in Table I”, etc. In one embodiment, the cancer protein is encoded by a nucleic acid of
“Heteroconjugate” antibodies are useful in the present methods and compositions. As used herein, the term “heteroconjugate antibody” refers to two covalently joined antibodies. Such antibodies can be prepared using known methods in synthetic protein chemistry, including using crosslinking agents. See, e.g., U.S. Pat. No. 4,676,980.
“High throughput screening” assays for the presence, absence, quantification, or other properties of particular nucleic acids or protein products are well known to those of skill in the art. Similarly, binding assays and reporter gene assays are similarly well known. Thus, e.g., U.S. Pat. No. 5,559,410 discloses high throughput screening methods for proteins; U.S. Pat. No. 5,585,639 discloses high throughput screening methods for nucleic acid binding (i.e., in arrays); while U.S. Pat. Nos. 5,576,220 and 5,541,061 disclose high throughput methods of screening for ligand/antibody binding.
In addition, high throughput screening systems are commercially available (see, e.g., Amersham Biosciences, Piscataway, N.J.; Zymark Corp., Hopkinton, Mass.; Air Technical Industries, Mentor, Ohio; Beckman Instruments, Inc. Fullerton, Calif.; Precision Systems, Inc., Natick, Mass.; etc.). These systems typically automate entire procedures, including all sample and reagent pipetting, liquid dispensing, timed incubations, and final readings of the microplate in detector(s) appropriate for the assay. These configurable systems provide high throughput and rapid start up as well as a high degree of flexibility and customization. The manufacturers of such systems provide detailed protocols for various high throughput systems. Thus, e.g., Zymark Corp. provides technical bulletins describing screening systems for detecting the modulation of gene transcription, ligand binding, and the like.
The term “homolog” refers to a molecule which exhibits homology to another molecule, by for example, having sequences of chemical residues that are the same or similar at corresponding positions.
In one embodiment, the antibody provided herein is a “human antibody.” As used herein, the term “human antibody” refers to an antibody in which essentially the entire sequences of the light chain and heavy chain sequences, including the complementary determining regions (CDRs), are from human genes. In one embodiment, human monoclonal antibodies are prepared by the trioma technique, the human B-cell technique (see, e.g., Kozbor, et al., Immunol. Today 4: 72 (1983), EBV transformation technique (see, e.g., Cole et al. MONOCLONAL ANTIBODIES AND CANCER THERAPY 77-96 (1985)), or using phage display (see, e.g., Marks et al., J. Mol. Biol. 222:581 (1991)). In a specific embodiment, the human antibody is generated in a transgenic mouse. Techniques for making such partially to fully human antibodies are known in the art and any such techniques can be used. According to one particularly preferred embodiment, fully human antibody sequences are made in a transgenic mouse engineered to express human heavy and light chain antibody genes. An exemplary description of preparing transgenic mice that produce human antibodies found in Application No. WO 02/43478 and U.S. Pat. No. 6,657,103 (Abgenix) and its progeny. B cells from transgenic mice that produce the desired antibody can then be fused to make hybridoma cell lines for continuous production of the antibody. See, e.g., U.S. Pat. Nos. 5,569,825; 5,625,126; 5,633,425; 5,661,016; and 5,545,806; and Jakobovits, Adv. Drug Del. Rev. 31:33-42 (1998); Green, et al., J. Exp. Med. 188:483-95 (1998).
“Human Leukocyte Antigen” or “HLA” is a human class I or class II Major Histocompatibility Complex (MHC) protein (see, e.g., Stites, et al., IMMUNOLOGY, 8TH ED., Lange Publishing, Los Altos, Calif. (1994).
As used herein, the term “humanized antibody” refers to forms of antibodies that contain sequences from non-human (e.g., murine) antibodies as well as human antibodies. Such antibodies are chimeric antibodies which contain minimal sequence derived from non-human immunoglobulin. In general, the humanized antibody will comprise substantially all of at least one, and typically two, variable domains, in which all or substantially all of the hypervariable loops correspond to those of a non-human immunoglobulin and all or substantially all of the FR regions are those of a human immunoglobulin sequence. The humanized antibody optionally also will comprise at least a portion of an immunoglobulin constant region (Fc), typically that of a human immunoglobulin. See e.g., Cabilly U.S. Pat. No. 4,816,567; Queen et al. (1989) Proc. Nat'l Acad. Sci. USA 86:10029-10033; and ANTIBODY ENGINEERING: A PRACTICAL APPROACH (Oxford University Press 1996).
The terms “hybridize”, “hybridizing”, “hybridizes” and the like, used in the context of polynucleotides, are meant to refer to conventional hybridization conditions, preferably such as hybridization in 50% formamide/6×SSC/0.1% SDS/100 μg/ml ssDNA, in which temperatures for hybridization are above 37 degrees C. and temperatures for washing in 0.1×SSC/0.1% SDS are above 55 degrees C.
The phrases “isolated” or “biologically pure” refer to material which is substantially or essentially free from components which normally accompany the material as it is found in its native state. Thus, isolated peptides in accordance with the invention preferably do not contain materials normally associated with the peptides in their in situ environment. For example, a polynucleotide is said to be “isolated” when it is substantially separated from contaminant polynucleotides that correspond or are complementary to genes other than the 24P4C12 genes or that encode polypeptides other than 24P4C12 gene product or fragments thereof. A skilled artisan can readily employ nucleic acid isolation procedures to obtain an isolated 24P4C12 polynucleotide. A protein is said to be “isolated,” for example, when physical, mechanical or chemical methods are employed to remove the 24P4C12 proteins from cellular constituents that are normally associated with the protein. A skilled artisan can readily employ standard purification methods to obtain an isolated 24P4C12 protein. Alternatively, an isolated protein can be prepared by chemical means.
Suitable “labels” include radionuclides, enzymes, substrates, cofactors, inhibitors, fluorescent moieties, chemiluminescent moieties, magnetic particles, and the like. Patents teaching the use of such labels include U.S. Pat. Nos. 3,817,837; 3,850,752; 3,939,350; 3,996,345; 4,277,437; 4,275,149; and 4,366,241. In addition, the antibodies provided herein can be useful as the antigen-binding component of fluorobodies. See e.g., Zeytun et al., Nat. Biotechnol. 21:1473-79 (2003).
The term “mammal” refers to any organism classified as a mammal, including mice, rats, rabbits, dogs, cats, cows, horses and humans. In one embodiment of the invention, the mammal is a mouse. In another embodiment of the invention, the mammal is a human.
The terms “metastatic cancer” and “metastatic disease” mean cancers that have spread to regional lymph nodes or to distant sites, and are meant to include stage D disease under the AUA system and stage T×N×M+under the TNM system.
The term “modulator” or “test compound” or “drug candidate” or grammatical equivalents as used herein describe any molecule, e.g., protein, oligopeptide, small organic molecule, polysaccharide, polynucleotide, etc., to be tested for the capacity to directly or indirectly alter the cancer phenotype or the expression of a cancer sequence, e.g., a nucleic acid or protein sequences, or effects of cancer sequences (e.g., signaling, gene expression, protein interaction, etc.) In one aspect, a modulator will neutralize the effect of a cancer protein of the invention. By “neutralize” is meant that an activity of a protein is inhibited or blocked, along with the consequent effect on the cell. In another aspect, a modulator will neutralize the effect of a gene, and its corresponding protein, of the invention by normalizing levels of said protein. In preferred embodiments, modulators alter expression profiles, or expression profile nucleic acids or proteins provided herein, or downstream effector pathways. In one embodiment, the modulator suppresses a cancer phenotype, e.g. to a normal tissue fingerprint. In another embodiment, a modulator induced a cancer phenotype. Generally, a plurality of assay mixtures is run in parallel with different agent concentrations to obtain a differential response to the various concentrations. Typically, one of these concentrations serves as a negative control, i.e., at zero concentration or below the level of detection.
Modulators, drug candidates or test compounds encompass numerous chemical classes, though typically they are organic molecules, preferably small organic compounds having a molecular weight of more than 100 and less than about 2,500 Daltons. Preferred small molecules are less than 2000, or less than 1500 or less than 1000 or less than 500 D. Candidate agents comprise functional groups necessary for structural interaction with proteins, particularly hydrogen bonding, and typically include at least an amine, carbonyl, hydroxyl or carboxyl group, preferably at least two of the functional chemical groups. The candidate agents often comprise cyclical carbon or heterocyclic structures and/or aromatic or polyaromatic structures substituted with one or more of the above functional groups. Modulators also comprise biomolecules such as peptides, saccharides, fatty acids, steroids, purines, pyrimidines, derivatives, structural analogs or combinations thereof. Particularly preferred are peptides. One class of modulators are peptides, for example of from about five to about 35 amino acids, with from about five to about 20 amino acids being preferred, and from about 7 to about 15 being particularly preferred. Preferably, the cancer modulatory protein is soluble, includes a non-transmembrane region, and/or, has an N-terminal Cys to aid in solubility. In one embodiment, the C-terminus of the fragment is kept as a free acid and the N-terminus is a free amine to aid in coupling, i.e., to cysteine. In one embodiment, a cancer protein of the invention is conjugated to an immunogenic agent as discussed herein. In one embodiment, the cancer protein is conjugated to BSA. The peptides of the invention, e.g., of preferred lengths, can be linked to each other or to other amino acids to create a longer peptide/protein. The modulatory peptides can be digests of naturally occurring proteins as is outlined above, random peptides, or “biased” random peptides. In a preferred embodiment, peptide/protein-based modulators are antibodies, and fragments thereof, as defined herein.
Modulators of cancer can also be nucleic acids. Nucleic acid modulating agents can be naturally occurring nucleic acids, random nucleic acids, or “biased” random nucleic acids. For example, digests of prokaryotic or eukaryotic genomes can be used in an approach analogous to that outlined above for proteins.
The term “monoclonal antibody”, as used herein, refers to an antibody obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies comprising the population are identical except for possible naturally occurring mutations that may be present in minor amounts. Monoclonal antibodies are highly specific, being directed against a single antigenic epitope. In contrast, conventional (polyclonal) antibody preparations typically include a multitude of antibodies directed against (or specific for) different epitopes. In one embodiment, the polyclonal antibody contains a plurality of monoclonal antibodies with different epitope specificities, affinities, or avidities within a single antigen that contains multiple antigenic epitopes. The modifier “monoclonal” indicates the character of the antibody as being obtained from a substantially homogeneous population of antibodies, and is not to be construed as requiring production of the antibody by any particular method. For example, the monoclonal antibodies to be used in accordance with the present invention may be made by the hybridoma method first described by Kohler et al., Nature 256: 495 (1975), or may be made by recombinant DNA methods (see, e.g., U.S. Pat. No. 4,816,567). The “monoclonal antibodies” may also be isolated from phage antibody libraries using the techniques described in Clackson et al., Nature 352: 624-628 (1991) and Marks et al., J. Mol. Biol. 222: 581-597 (1991), for example. These monoclonal antibodies will usually bind with at least a Kd of about 1 μM, more usually at least about 300 nM, typically at least about 30 nM, preferably at least about 10 nM, more preferably at least about 3 nM or better, usually determined by ELISA.
A “motif”, as in biological motif of a 24P4C12-related protein, refers to any pattern of amino acids forming part of the primary sequence of a protein, that is associated with a particular function (e.g. protein-protein interaction, protein-DNA interaction, etc) or modification (e.g. that is phosphorylated, glycosylated or amidated), or localization (e.g. secretory sequence, nuclear localization sequence, etc.) or a sequence that is correlated with being immunogenic, either humorally or cellularly. A motif can be either contiguous or capable of being aligned to certain positions that are generally correlated with a certain function or property. In the context of HLA motifs, “motif” refers to the pattern of residues in a peptide of defined length, usually a peptide of from about 8 to about 13 amino acids for a class I HLA motif and from about 6 to about 25 amino acids for a class II HLA motif, which is recognized by a particular HLA molecule. Peptide motifs for HLA binding are typically different for each protein encoded by each human HLA allele and differ in the pattern of the primary and secondary anchor residues. Frequently occurring motifs are set forth in Table V.
A “pharmaceutical excipient” comprises a material such as an adjuvant, a carrier, pH-adjusting and buffering agents, tonicity adjusting agents, wetting agents, preservative, and the like.
“Pharmaceutically acceptable” refers to a non-toxic, inert, and/or composition that is physiologically compatible with humans or other mammals.
The term “polynucleotide” means a polymeric form of nucleotides of at least 10 bases or base pairs in length, either ribonucleotides or deoxynucleotides or a modified form of either type of nucleotide, and is meant to include single and double stranded forms of DNA and/or RNA. In the art, this term if often used interchangeably with “oligonucleotide”. A polynucleotide can comprise a nucleotide sequence disclosed herein wherein thymidine (T), as shown for example in
The term “polypeptide” means a polymer of at least about 4, 5, 6, 7, or 8 amino acids. Throughout the specification, standard three letter or single letter designations for amino acids are used. In the art, this term is often used interchangeably with “peptide” or “protein”.
An HLA “primary anchor residue” is an amino acid at a specific position along a peptide sequence which is understood to provide a contact point between the immunogenic peptide and the HLA molecule. One to three, usually two, primary anchor residues within a peptide of defined length generally defines a “motif” for an immunogenic peptide. These residues are understood to fit in close contact with peptide binding groove of an HLA molecule, with their side chains buried in specific pockets of the binding groove. In one embodiment, for example, the primary anchor residues for an HLA class I molecule are located at position 2 (from the amino terminal position) and at the carboxyl terminal position of a 8, 9, 10, 11, or 12 residue peptide epitope in accordance with the invention. Alternatively, in another embodiment, the primary anchor residues of a peptide binds an HLA class II molecule are spaced relative to each other, rather than to the termini of a peptide, where the peptide is generally of at least 9 amino acids in length. The primary anchor positions for each motif and supermotif are set forth in Table IV(a). For example, analog peptides can be created by altering the presence or absence of particular residues in the primary and/or secondary anchor positions shown in Table IV. Such analogs are used to modulate the binding affinity and/or population coverage of a peptide comprising a particular HLA motif or supermotif.
“Radioisotopes” include, but are not limited to the following (non-limiting exemplary uses are also set forth in Table IV(I)).
By “randomized” or grammatical equivalents as herein applied to nucleic acids and proteins is meant that each nucleic acid and peptide consists of essentially random nucleotides and amino acids, respectively. These random peptides (or nucleic acids, discussed herein) can incorporate any nucleotide or amino acid at any position. The synthetic process can be designed to generate randomized proteins or nucleic acids, to allow the formation of all or most of the possible combinations over the length of the sequence, thus forming a library of randomized candidate bioactive proteinaceous agents.
In one embodiment, a library is “fully randomized,” with no sequence preferences or constants at any position. In another embodiment, the library is a “biased random” library. That is, some positions within the sequence either are held constant, or are selected from a limited number of possibilities. For example, the nucleotides or amino acid residues are randomized within a defined class, e.g., of hydrophobic amino acids, hydrophilic residues, sterically biased (either small or large) residues, towards the creation of nucleic acid binding domains, the creation of cysteines, for cross-linking, prolines for SH-3 domains, serines, threonines, tyrosines or histidines for phosphorylation sites, etc., or to purines, etc.
A “recombinant” DNA or RNA molecule is a DNA or RNA molecule that has been subjected to molecular manipulation in vitro.
As used herein, the term “single-chain Fv” or “scFv” or “single chain” antibody refers to antibody fragments comprising the VH and VL domains of antibody, wherein these domains are present in a single polypeptide chain. Generally, the Fv polypeptide further comprises a polypeptide linker between the VH and VL domains which enables the sFv to form the desired structure for antigen binding. For a review of sFv, see Pluckthun, THE PHARMACOLOGY OF MONOCLONAL ANTIBODIES, vol. 113, Rosenburg and Moore eds. Springer-Verlag, New York, pp. 269-315 (1994).
Non-limiting examples of “small molecules” include compounds that bind or interact with 24P4C12, ligands including hormones, neuropeptides, chemokines, odorants, phospholipids, amino acids, polyamines, carbohydrates, steroids, minerals, vitamins, fatty acids, nucleotides, alcohols and functional equivalents or derivatives thereof that bind and preferably inhibit 24P4C12 protein function. Such non-limiting small molecules preferably have a molecular weight of less than about 10 kDa, more preferably below about 9, about 8, about 7, about 6, about 5 or about 4 kDa. In certain embodiments, small molecules physically associate with, or bind, 24P4C12 protein; are not found in naturally occurring metabolic pathways; and/or are more soluble in aqueous than non-aqueous solutions.
As used herein, the term “specific” refers to the selective binding of the antibody to the target antigen epitope. Antibodies can be tested for specificity of binding by comparing binding to appropriate antigen to binding to irrelevant antigen or antigen mixture under a given set of conditions. If the antibody binds to the appropriate antigen at least 2, 5, 7, and preferably 10 times more than to irrelevant antigen or antigen mixture then it is considered to be specific. In one embodiment, a specific antibody is one that only binds the 24P4C12 antigen, but does not bind to the irrelevent antigen. In another embodiment, a specific antibody is one that binds human 24P4C12 antigen but does not bind a non-human 24P4C12 antigen with 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or greater amino acid homology with the 24P4C12 antigen. In another embodiment, a specific antibody is one that binds human 24P4C12 antigen and binds murine 24P4C12 antigen, but with a higher degree of binding the human antigen. In another embodiment, a specific antibody is one that binds human 24P4C12 antigen and binds primate 24P4C12 antigen, but with a higher degree of binding the human antigen. In another embodiment, the specific antibody binds to human 24P4C12 antigen and any non-human 24P4C12 antigen, but with a higher degree of binding the human antigen or any combination thereof.
“Stringency” of hybridization reactions is readily determinable by one of ordinary skill in the art, and generally is an empirical calculation dependent upon probe length, washing temperature, and salt concentration. In general, longer probes require higher temperatures for proper annealing, while shorter probes need lower temperatures. Hybridization generally depends on the ability of denatured nucleic acid sequences to reanneal when complementary strands are present in an environment below their melting temperature. The higher the degree of desired homology between the probe and hybridizable sequence, the higher the relative temperature that can be used. As a result, it follows that higher relative temperatures would tend to make the reaction conditions more stringent, while lower temperatures less so. For additional details and explanation of stringency of hybridization reactions, see Ausubel et al., Current Protocols in Molecular Biology, Wiley Interscience Publishers, (1995).
“Stringent conditions” or “high stringency conditions”, as defined herein, are identified by, but not limited to, those that: (1) employ low ionic strength and high temperature for washing, for example 0.015 M sodium chloride/0.0015 M sodium citrate/0.1% sodium dodecyl sulfate at 50° C.; (2) employ during hybridization a denaturing agent, such as formamide, for example, 50% (v/v) formamide with 0.1% bovine serum albumin/0.1% Ficoll/0.1% polyvinylpyrrolidone/50 mM sodium phosphate buffer at pH 6.5 with 750 mM sodium chloride, 75 mM sodium citrate at 42° C.; or (3) employ 50% formamide, 5×SSC (0.75 M NaCl, 0.075 M sodium citrate), 50 mM sodium phosphate (pH 6.8), 0.1% sodium pyrophosphate, 5×Denhardt's solution, sonicated salmon sperm DNA (50 μg/ml), 0.1% SDS, and 10% dextran sulfate at 42° C., with washes at 42° C. in 0.2×SSC (sodium chloride/sodium citrate) and 50% formamide at 55° C., followed by a high-stringency wash consisting of 0.1×SSC containing EDTA at 55° C. “Moderately stringent conditions” are described by, but not limited to, those in Sambrook et al., Molecular Cloning: A Laboratory Manual, New York: Cold Spring Harbor Press, 1989, and include the use of washing solution and hybridization conditions (e.g., temperature, ionic strength and % SDS) less stringent than those described above. An example of moderately stringent conditions is overnight incubation at 65° C. in a solution comprising: 1% bovine serum albumin, 0.5M sodium phosphate pH7.5, 1.25 mM EDTA, and 7% SDS 5×SSC (150 mM NaCl, 15 mM trisodium citrate), followed by washing the filters in 2×SSC/1% SDS at 50° C. and 0.2×SSC/0.1% SDS at 50° C. The skilled artisan will recognize how to adjust the temperature, ionic strength, etc. as necessary to accommodate factors such as probe length and the like.
An HLA “supermotif” is a peptide binding specificity shared by HLA molecules encoded by two or more HLA alleles. Overall phenotypic frequencies of HLA-supertypes in different ethnic populations are set forth in Table IV (f). The non-limiting constituents of various supertypes are as follows:
A2: A*0201, A*0202, A*0203, A*0204, A*0205, A*0206, A*6802, A*6901, A*0207
A3: A3, A11, A31, A*3301, A*6801, A*0301, A*1101, A*3101
B7: B7, B*3501-03, B*51, B*5301, B*5401, B*5501, B*5502, B*5601, B*6701, B*7801, B*0702, B*5101, B*5602
B44: B*3701, B*4402, B*4403, B*60 (B*4001), B61 (B*4006)
A1: A*0102, A*2604, A*3601, A*4301, A*8001
A24: A*24, A*30, A*2403, A*2404, A*3002, A*3003
B27: B*1401-02, B*1503, B*1509, B*1510, B*1518, B*3801-02, B*3901, B*3902, B*3903-04, B*4801-02, B*7301, B*2701-08
B58: B*1516, B*1517, B*5701, B*5702, B58
B62: B*4601, B52, B*1501 (B62), B*1502 (B75), B*1513 (B77)
Calculated population coverage afforded by different HLA-supertype combinations are set forth in Table IV(g).
As used herein “to treat” or “therapeutic” and grammatically related terms, refer to any improvement of any consequence of disease, such as prolonged survival, less morbidity, and/or a lessening of side effects which are the byproducts of an alternative therapeutic modality; as is readily appreciated in the art, full eradication of disease is a preferred out albeit not a requirement for a treatment act.
A “transgenic animal” (e.g., a mouse or rat) is an animal having cells that contain a transgene, which transgene was introduced into the animal or an ancestor of the animal at a prenatal, e.g., an embryonic stage. A “transgene” is a DNA that is integrated into the genome of a cell from which a transgenic animal develops.
As used herein, an HLA or cellular immune response “vaccine” is a composition that contains or encodes one or more peptides of the invention. There are numerous embodiments of such vaccines, such as a cocktail of one or more individual peptides; one or more peptides of the invention comprised by a polyepitopic peptide; or nucleic acids that encode such individual peptides or polypeptides, e.g., a minigene that encodes a polyepitopic peptide. The “one or more peptides” can include any whole unit integer from 1-150 or more, e.g., at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, or 150 or more peptides of the invention. The peptides or polypeptides can optionally be modified, such as by lipidation, addition of targeting or other sequences. HLA class I peptides of the invention can be admixed with, or linked to, HLA class II peptides, to facilitate activation of both cytotoxic T lymphocytes and helper T lymphocytes. HLA vaccines can also comprise peptide-pulsed antigen presenting cells, e.g., dendritic cells.
The term “variant” refers to a molecule that exhibits a variation from a described type or norm, such as a protein that has one or more different amino acid residues in the corresponding position(s) of a specifically described protein (e.g. the 24P4C12 protein shown in
The “24P4C12-related proteins” of the invention include those specifically identified herein, as well as allelic variants, conservative substitution variants, analogs and homologs that can be isolated/generated and characterized without undue experimentation following the methods outlined herein or readily available in the art. Fusion proteins that combine parts of different 24P4C12 proteins or fragments thereof, as well as fusion proteins of a 24P4C12 protein and a heterologous polypeptide are also included. Such 24P4C12 proteins are collectively referred to as the 24P4C12-related proteins, the proteins of the invention, or 24P4C12. The term “24P4C12-related protein” refers to a polypeptide fragment or a 24P4C12 protein sequence of 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or more than 25 amino acids; or, at least 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 225, 250, 275, 300, 325, 330, 335, 339 or more amino acids.
II.) 24P4C12 Polynucleotides
One aspect of the invention provides polynucleotides corresponding or complementary to all or part of a 24P4C12 gene, mRNA, and/or coding sequence, preferably in isolated form, including polynucleotides encoding a 24P4C12-related protein and fragments thereof, DNA, RNA, DNA/RNA hybrid, and related molecules, polynucleotides or oligonucleotides complementary to a 24P4C12 gene or mRNA sequence or a part thereof, and polynucleotides or oligonucleotides that hybridize to a 24P4C12 gene, mRNA, or to a 24P4C12 encoding polynucleotide (collectively, “24P4C12 polynucleotides”). In all instances when referred to in this section, T can also be U in
Embodiments of a 24P4C12 polynucleotide include: a 24P4C12 polynucleotide having the sequence shown in
Polynucleotides encoding relatively long portions of a 24P4C12 protein are also within the scope of the invention. For example, polynucleotides encoding from about amino acid 1 (or 20 or 30 or 40 etc.) to about amino acid 20, (or 30, or 40 or 50 etc.) of the 24P4C12 protein “or variant” shown in
II.A.) Uses of 24P4C12 Polynucleotides
II.A.1. Monitoring of Genetic Abnormalities
The polynucleotides of the preceding paragraphs have a number of different specific uses. The human 24P4C12 gene maps to the chromosomal location set forth in the Example entitled “Chromosomal Mapping of 24P4C12.” For example, because the 24P4C12 gene maps to this chromosome, polynucleotides that encode different regions of the 24P4C12 proteins are used to characterize cytogenetic abnormalities of this chromosomal locale, such as abnormalities that are identified as being associated with various cancers. In certain genes, a variety of chromosomal abnormalities including rearrangements have been identified as frequent cytogenetic abnormalities in a number of different cancers (see e.g. Krajinovic et al., Mutat. Res. 382(3-4): 81-83 (1998); Johansson et al., Blood 86(10): 3905-3914 (1995) and Finger et al., P.N.A.S. 85(23): 9158-9162 (1988)). Thus, polynucleotides encoding specific regions of the 24P4C12 proteins provide new tools that can be used to delineate, with greater precision than previously possible, cytogenetic abnormalities in the chromosomal region that encodes 24P4C12 that may contribute to the malignant phenotype. In this context, these polynucleotides satisfy a need in the art for expanding the sensitivity of chromosomal screening in order to identify more subtle and less common chromosomal abnormalities (see e.g. Evans et al., Am. J. Obstet. Gynecol 171(4): 1055-1057 (1994)).
Furthermore, as 24P4C12 was shown to be highly expressed in prostate and other cancers, 24P4C12 polynucleotides are used in methods assessing the status of 24P4C12 gene products in normal versus cancerous tissues. Typically, polynucleotides that encode specific regions of the 24P4C12 proteins are used to assess the presence of perturbations (such as deletions, insertions, point mutations, or alterations resulting in a loss of an antigen etc.) in specific regions of the 24P4C12 gene, such as regions containing one or more motifs. Exemplary assays include both RT-PCR assays as well as single-strand conformation polymorphism (SSCP) analysis (see, e.g., Marrogi et al., J. Cutan. Pathol. 26(8): 369-378 (1999), both of which utilize polynucleotides encoding specific regions of a protein to examine these regions within the protein.
II.A.2. Antisense Embodiments
Other specifically contemplated nucleic acid related embodiments of the invention disclosed herein are genomic DNA, cDNAs, ribozymes, and antisense molecules, as well as nucleic acid molecules based on an alternative backbone, or including alternative bases, whether derived from natural sources or synthesized, and include molecules capable of inhibiting the RNA or protein expression of 24P4C12. For example, antisense molecules can be RNAs or other molecules, including peptide nucleic acids (PNAs) or non-nucleic acid molecules such as phosphorothioate derivatives that specifically bind DNA or RNA in a base pair-dependent manner. A skilled artisan can readily obtain these classes of nucleic acid molecules using the 24P4C12 polynucleotides and polynucleotide sequences disclosed herein.
Antisense technology entails the administration of exogenous oligonucleotides that bind to a target polynucleotide located within the cells. The term “antisense” refers to the fact that such oligonucleotides are complementary to their intracellular targets, e.g., 24P4C12. See for example, Jack Cohen, Oligodeoxynucleotides, Antisense Inhibitors of Gene Expression, CRC Press, 1989; and Synthesis 1:1-5 (1988). The 24P4C12 antisense oligonucleotides of the present invention include derivatives such as S-oligonucleotides (phosphorothioate derivatives or S-oligos, see, Jack Cohen, supra), which exhibit enhanced cancer cell growth inhibitory action. S-oligos (nucleoside phosphorothioates) are isoelectronic analogs of an oligonucleotide (O-oligo) in which a nonbridging oxygen atom of the phosphate group is replaced by a sulfur atom. The S-oligos of the present invention can be prepared by treatment of the corresponding O-oligos with 3H-1,2-benzodithiol-3-one-1,1-dioxide, which is a sulfur transfer reagent. See, e.g., Iyer, R. P. et al., J. Org. Chem. 55:4693-4698 (1990); and Iyer, R. P. et al., J. Am. Chem. Soc. 112:1253-1254 (1990). Additional 24P4C12 antisense oligonucleotides of the present invention include morpholino antisense oligonucleotides known in the art (see, e.g., Partridge et al., 1996, Antisense & Nucleic Acid Drug Development 6: 169-175).
The 24P4C12 antisense oligonucleotides of the present invention typically can be RNA or DNA that is complementary to and stably hybridizes with the first 100 5′ codons or last 100 3′ codons of a 24P4C12 genomic sequence or the corresponding mRNA. Absolute complementarity is not required, although high degrees of complementarity are preferred. Use of an oligonucleotide complementary to this region allows for the selective hybridization to 24P4C12 mRNA and not to mRNA specifying other regulatory subunits of protein kinase. In one embodiment, 24P4C12 antisense oligonucleotides of the present invention are 15 to 30-mer fragments of the antisense DNA molecule that have a sequence that hybridizes to 24P4C12 mRNA. Optionally, 24P4C12 antisense oligonucleotide is a 30-mer oligonucleotide that is complementary to a region in the first 10 5′ codons or last 10 3′ codons of 24P4C12. Alternatively, the antisense molecules are modified to employ ribozymes in the inhibition of 24P4C12 expression, see, e.g., L. A. Couture & D. T. Stinchcomb; Trends Genet. 12: 510-515 (1996).
II.A.3. Primers and Primer Pairs
Further specific embodiments of these nucleotides of the invention include primers and primer pairs, which allow the specific amplification of polynucleotides of the invention or of any specific parts thereof, and probes that selectively or specifically hybridize to nucleic acid molecules of the invention or to any part thereof. Probes can be labeled with a detectable marker, such as, for example, a radioisotope, fluorescent compound, bioluminescent compound, a chemiluminescent compound, metal chelator or enzyme. Such probes and primers are used to detect the presence of a 24P4C12 polynucleotide in a sample and as a means for detecting a cell expressing a 24P4C12 protein.
Examples of such probes include polypeptides comprising all or part of the human 24P4C12 cDNA sequence shown in
The 24P4C12 polynucleotides of the invention are useful for a variety of purposes, including but not limited to their use as probes and primers for the amplification and/or detection of the 24P4C12 gene(s), mRNA(s), or fragments thereof; as reagents for the diagnosis and/or prognosis of prostate cancer and other cancers; as coding sequences capable of directing the expression of 24P4C12 polypeptides; as tools for modulating or inhibiting the expression of the 24P4C12 gene(s) and/or translation of the 24P4C12 transcript(s); and as therapeutic agents.
The present invention includes the use of any probe as described herein to identify and isolate a 24P4C12 or 24P4C12 related nucleic acid sequence from a naturally occurring source, such as humans or other mammals, as well as the isolated nucleic acid sequence per se, which would comprise all or most of the sequences found in the probe used.
II.A.4. Isolation of 24P4C12-Encoding Nucleic Acid Molecules
The 24P4C12 cDNA sequences described herein enable the isolation of other polynucleotides encoding 24P4C12 gene product(s), as well as the isolation of polynucleotides encoding 24P4C12 gene product homologs, alternatively spliced isoforms, allelic variants, and mutant forms of a 24P4C12 gene product as well as polynucleotides that encode analogs of 24P4C12-related proteins. Various molecular cloning methods that can be employed to isolate full length cDNAs encoding a 24P4C12 gene are well known (see, for example, Sambrook, J. et al., Molecular Cloning: A Laboratory Manual, 2d edition, Cold Spring Harbor Press, New York, 1989; Current Protocols in Molecular Biology. Ausubel et al., Eds., Wiley and Sons, 1995). For example, lambda phage cloning methodologies can be conveniently employed, using commercially available cloning systems (e.g., Lambda ZAP Express, Stratagene). Phage clones containing 24P4C12 gene cDNAs can be identified by probing with a labeled 24P4C12 cDNA or a fragment thereof. For example, in one embodiment, a 24P4C12 cDNA (e.g.,
II.A.5. Recombinant Nucleic Acid Molecules and Host-Vector Systems
The invention also provides recombinant DNA or RNA molecules containing a 24P4C12 polynucleotide, a fragment, analog or homologue thereof, including but not limited to phages, plasmids, phagemids, cosmids, YACs, BACs, as well as various viral and non-viral vectors well known in the art, and cells transformed or transfected with such recombinant DNA or RNA molecules. Methods for generating such molecules are well known (see, for example, Sambrook et al., 1989, supra).
The invention further provides a host-vector system comprising a recombinant DNA molecule containing a 24P4C12 polynucleotide, fragment, analog or homologue thereof within a suitable prokaryotic or eukaryotic host cell. Examples of suitable eukaryotic host cells include a yeast cell, a plant cell, or an animal cell, such as a mammalian cell or an insect cell (e.g., a baculovirus-infectible cell such as an Sf9 or HighFive cell). Examples of suitable mammalian cells include various prostate cancer cell lines such as DU145 and TsuPr1, other transfectable or transducible prostate cancer cell lines, primary cells (PrEC), as well as a number of mammalian cells routinely used for the expression of recombinant proteins (e.g., COS, CHO, 293, 293T cells). More particularly, a polynucleotide comprising the coding sequence of 24P4C12 or a fragment, analog or homolog thereof can be used to generate 24P4C12 proteins or fragments thereof using any number of host-vector systems routinely used and widely known in the art.
A wide range of host-vector systems suitable for the expression of 24P4C12 proteins or fragments thereof are available, see for example, Sambrook et al., 1989, supra; Current Protocols in Molecular Biology, 1995, supra). Preferred vectors for mammalian expression include but are not limited to pcDNA 3.1 myc-His-tag (Invitrogen) and the retroviral vector pSR tkneo (Muller et al., 1991, MCB 11:1785). Using these expression vectors, 24P4C12 can be expressed in several prostate cancer and non-prostate cell lines, including for example 293, 293T, rat-1, PC3, NIH 3T3 and TsuPr1. The host-vector systems of the invention are useful for the production of a 24P4C12 protein or fragment thereof. Such host-vector systems can be employed to study the functional properties of 24P4C12 and 24P4C12 mutations or analogs.
Recombinant human 24P4C12 protein or an analog or homolog or fragment thereof can be produced by mammalian cells transfected with a construct encoding a 24P4C12-related nucleotide. For example, 293T cells can be transfected with an expression plasmid encoding 24P4C12 or fragment, analog or homolog thereof, a 24P4C12-related protein is expressed in the 293T cells, and the recombinant 24P4C12 protein is isolated using standard purification methods (e.g., affinity purification using anti-24P4C12 antibodies). In another embodiment, a 24P4C12 coding sequence is subcloned into the retroviral vector pSRαMSVtkneo and used to infect various mammalian cell lines, such as NIH 3T3, TsuPr1, PC3, 293 and rat-1 in order to establish 24P4C12 expressing cell lines. Various other expression systems well known in the art can also be employed. Expression constructs encoding a leader peptide joined in frame to a 24P4C12 coding sequence can be used for the generation of a secreted form of recombinant 24P4C12 protein.
As discussed herein, redundancy in the genetic code permits variation in 24P4C12 gene sequences. In particular, it is known in the art that specific host species often have specific codon preferences, and thus one can adapt the disclosed sequence as preferred for a desired host. For example, preferred analog codon sequences typically have rare codons (i.e., codons having a usage frequency of less than about 20% in known sequences of the desired host) replaced with higher frequency codons. Codon preferences for a specific species are calculated, for example, by utilizing codon usage tables available on the INTERNET.
Additional sequence modifications are known to enhance protein expression in a cellular host. These include elimination of sequences encoding spurious polyadenylation signals, exon/intron splice site signals, transposon-like repeats, and/or other such well-characterized sequences that are deleterious to gene expression. The GC content of the sequence is adjusted to levels average for a given cellular host, as calculated by reference to known genes expressed in the host cell. Where possible, the sequence is modified to avoid predicted hairpin secondary mRNA structures. Other useful modifications include the addition of a translational initiation consensus sequence at the start of the open reading frame, as described in Kozak, Mol. Cell. Biol., 9:5073-5080 (1989). Skilled artisans understand that the general rule that eukaryotic ribosomes initiate translation exclusively at the 5′ proximal AUG codon is abrogated only under rare conditions (see, e.g., Kozak PNAS 92(7): 2662-2666, (1995) and Kozak NAR 15(20): 8125-8148 (1987)).
III.) 24P4C12-Related Proteins
Another aspect of the present invention provides 24P4C12-related proteins. Specific embodiments of 24P4C12 proteins comprise a polypeptide having all or part of the amino acid sequence of human 24P4C12 as shown in
Embodiments of a 24P4C12 polypeptide include: a 24P4C12 polypeptide having a sequence shown in
Amino acid abbreviations are provided in Table II. Conservative amino acid substitutions can frequently be made in a protein without altering either the conformation or the function of the protein. Proteins of the invention can comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 conservative substitutions.
Embodiments of the invention disclosed herein include a wide variety of art-accepted variants or analogs of 24P4C12 proteins such as polypeptides having amino acid insertions, deletions and substitutions. 24P4C12 variants can be made using methods known in the art such as site-directed mutagenesis, alanine scanning, and PCR mutagenesis. Site-directed mutagenesis (Carter et al., Nucl. Acids Res., 13:4331 (1986); Zoller et al., Nucl. Acids Res., 10:6487 (1987)), cassette mutagenesis (Wells et al., Gene, 34:315 (1985)), restriction selection mutagenesis (Wells et al., Philos. Trans. R. Soc. London SerA, 317:415 (1986)) or other known techniques can be performed on the cloned DNA to produce the 24P4C12 variant DNA.
Scanning amino acid analysis can also be employed to identify one or more amino acids along a contiguous sequence that is involved in a specific biological activity such as a protein-protein interaction. Among the preferred scanning amino acids are relatively small, neutral amino acids. Such amino acids include alanine, glycine, serine, and cysteine. Alanine is typically a preferred scanning amino acid among this group because it eliminates the side-chain beyond the beta-carbon and is less likely to alter the main-chain conformation of the variant. Alanine is also typically preferred because it is the most common amino acid. Further, it is frequently found in both buried and exposed positions (Creighton, The Proteins, (W.H. Freeman & Co., N.Y.); Chothia, J. Mol. Biol., 150:1 (1976)). If alanine substitution does not yield adequate amounts of variant, an isosteric amino acid can be used.
As defined herein, 24P4C12 variants, analogs or homologs, have the distinguishing attribute of having at least one epitope that is “cross reactive” with a 24P4C12 protein having an amino acid sequence of
Other classes of 24P4C12-related protein variants share 70%, 75%, 80%, 85%, 90%, 95% or more similarity with an amino acid sequence of
As discussed herein, embodiments of the claimed invention include polypeptides containing less than the full amino acid sequence of a 24P4C12 protein shown in
24P4C12-related proteins are generated using standard peptide synthesis technology or using chemical cleavage methods well known in the art. Alternatively, recombinant methods can be used to generate nucleic acid molecules that encode a 24P4C12-related protein. In one embodiment, nucleic acid molecules provide a means to generate defined fragments of a 24P4C12 protein (or variants, homologs or analogs thereof).
III.A.) Motif-Bearing Protein Embodiments
Additional illustrative embodiments of the invention disclosed herein include 24P4C12 polypeptides comprising the amino acid residues of one or more of the biological motifs contained within a 24P4C12 polypeptide sequence set forth in
Motif bearing subsequences of all 24P4C12 variant proteins have previously been disclosed.
Table IV(h) sets forth several frequently occurring motifs based on pfam searches (see URL address pfam.wustl.edu/). The columns of Table IV(h) list (1) motif name abbreviation, (2) percent identity found amongst the different member of the motif family, (3) motif name or description and (4) most common function; location information is included if the motif is relevant for location.
Polypeptides comprising one or more of the 24P4C12 motifs discussed above are useful in elucidating the specific characteristics of a malignant phenotype in view of the observation that the 24P4C12 motifs discussed above are associated with growth dysregulation and because 24P4C12 is overexpressed in certain cancers (See, e.g., Table I). Casein kinase II, cAMP and camp-dependent protein kinase, and Protein Kinase C, for example, are enzymes known to be associated with the development of the malignant phenotype (see e.g. Chen et al., Lab Invest., 78(2): 165-174 (1998); Gaiddon et al., Endocrinology 136(10): 4331-4338 (1995); Hall et al., Nucleic Acids Research 24(6): 1119-1126 (1996); Peterziel et al., Oncogene 18(46): 6322-6329 (1999) and O'Brian, Oncol. Rep. 5(2): 305-309 (1998)). Moreover, both glycosylation and myristoylation are protein modifications also associated with cancer and cancer progression (see e.g. Dennis et al., Biochem. Biophys. Acta 1473(1):21-34 (1999); Raju et al., Exp. Cell Res. 235(1): 145-154 (1997)). Amidation is another protein modification also associated with cancer and cancer progression (see e.g. Treston et al., J. Natl. Cancer Inst. Monogr. (13): 169-175 (1992)).
In another embodiment, proteins of the invention comprise one or more of the immunoreactive epitopes identified in accordance with art-accepted methods, such as the peptides previously disclosed. CTL epitopes can be determined using specific algorithms to identify peptides within a 24P4C12 protein that are capable of optimally binding to specified HLA alleles (e.g., Table IV; Epimatrix™ and Epimer™, Brown University, URL brown.edu/Research/TB-HIV_Lab/epimatrix/epimatrix.html and BIMAS, URL bimas.dcrt.nih.gov/.) Moreover, processes for identifying peptides that have sufficient binding affinity for HLA molecules and which are correlated with being immunogenic epitopes, are well known in the art, and are carried out without undue experimentation. In addition, processes for identifying peptides that are immunogenic epitopes, are well known in the art, and are carried out without undue experimentation either in vitro or in vivo.
Also known in the art are principles for creating analogs of such epitopes in order to modulate immunogenicity. For example, one begins with an epitope that bears a CTL or HTL motif (see, e.g., the HLA Class I and HLA Class II motifs/supermotifs of Table IV). The epitope is analoged by substituting out an amino acid at one of the specified positions, and replacing it with another amino acid specified for that position. For example, on the basis of residues defined in Table IV, one can substitute out a deleterious residue in favor of any other residue, such as a preferred residue; substitute a less-preferred residue with a preferred residue; or substitute an originally-occurring preferred residue with another preferred residue. Substitutions can occur at primary anchor positions or at other positions in a peptide; see, e.g., Table IV.
A variety of references reflect the art regarding the identification and generation of epitopes in a protein of interest as well as analogs thereof. See, for example, WO 97/33602 to Chesnut et al.; Sette, Immunogenetics 1999 50(3-4): 201-212; Sette et al., J. Immunol. 2001 166(2): 1389-1397; Sidney et al., Hum. Immunol. 1997 58(1): 12-20; Kondo et al., Immunogenetics 1997 45(4): 249-258; Sidney et al., J. Immunol. 1996 157(8): 3480-90; and Falk et al., Nature 351: 290-6 (1991); Hunt et al., Science 255:1261-3 (1992); Parker et al., J. Immunol. 149:3580-7 (1992); Parker et al., J. Immunol. 152:163-75 (1994)); Kast et al., 1994 152(8): 3904-12; Borras-Cuesta et al., Hum. Immunol. 2000 61(3): 266-278; Alexander et al., J. Immunol. 2000 164(3); 164(3): 1625-1633; Alexander et al., PMID: 7895164, UI: 95202582; O'Sullivan et al., J. Immunol. 1991 147(8): 2663-2669; Alexander et al., Immunity 1994 1(9): 751-761 and Alexander et al., Immunol. Res. 1998 18(2): 79-92.
Related embodiments of the invention include polypeptides comprising combinations of the different motifs set forth in Table(s) IV(a), IV(b), IV(c), IV(d), and IV(h), and/or, one or more of the predicted CTL epitopes of previously disclosed, and/or, one or more of the T cell binding motifs known in the art. Preferred embodiments contain no insertions, deletions or substitutions either within the motifs or within the intervening sequences of the polypeptides. In addition, embodiments which include a number of either N-terminal and/or C-terminal amino acid residues on either side of these motifs may be desirable (to, for example, include a greater portion of the polypeptide architecture in which the motif is located). Typically, the number of N-terminal and/or C-terminal amino acid residues on either side of a motif is between about 1 to about 100 amino acid residues, preferably 5 to about 50 amino acid residues.
24P4C12-related proteins are embodied in many forms, preferably in isolated form. A purified 24P4C12 protein molecule will be substantially free of other proteins or molecules that impair the binding of 24P4C12 to antibody, T cell or other ligand. The nature and degree of isolation and purification will depend on the intended use. Embodiments of 24P4C12-related proteins include purified 24P4C12-related proteins and functional, soluble 24P4C12-related proteins. In one embodiment, a functional, soluble 24P4C12 protein or fragment thereof retains the ability to be bound by antibody, T cell or other ligand.
The invention also provides 24P4C12 proteins comprising biologically active fragments of a 24P4C12 amino acid sequence shown in
24P4C12-related polypeptides that contain particularly interesting structures can be predicted and/or identified using various analytical techniques well known in the art, including, for example, the methods of Chou-Fasman, Garnier-Robson, Kyte-Doolittle, Eisenberg, Karplus-Schultz or Jameson-Wolf analysis, or based on immunogenicity. Fragments that contain such structures are particularly useful in generating subunit-specific anti-24P4C12 antibodies or T cells or in identifying cellular factors that bind to 24P4C12. For example, hydrophilicity profiles can be generated, and immunogenic peptide fragments identified, using the method of Hopp, T. P. and Woods, K. R., 1981, Proc. Natl. Acad. Sci. U.S.A. 78:3824-3828. Hydropathicity profiles can be generated, and immunogenic peptide fragments identified, using the method of Kyte, J. and Doolittle, R. F., 1982, J. Mol. Biol. 157:105-132. Percent (%) Accessible Residues profiles can be generated, and immunogenic peptide fragments identified, using the method of Janin J., 1979, Nature 277:491-492. Average Flexibility profiles can be generated, and immunogenic peptide fragments identified, using the method of Bhaskaran R., Ponnuswamy P. K., 1988, Int. J. Pept. Protein Res. 32:242-255. Beta-turn profiles can be generated, and immunogenic peptide fragments identified, using the method of Deleage, G., Roux B., 1987, Protein Engineering 1:289-294.
CTL epitopes can be determined using specific algorithms to identify peptides within a 24P4C12 protein that are capable of optimally binding to specified HLA alleles such as BIMAS and SYFPEITHI. Illustrating this, peptide epitopes from 24P4C12 that are presented in the context of human MHC Class 1 molecules, e.g., HLA-A1, A2, A3, A11, A24, B7 and B35 were predicted. Specifically, the complete amino acid sequence of the 24P4C12 protein and relevant portions of other variants, i.e., for HLA Class I predictions 9 flanking residues on either side of a point mutation or exon junction, and for HLA Class II predictions 14 flanking residues on either side of a point mutation or exon junction corresponding to that variant, were entered into the HLA Peptide Motif Search algorithm found in the Bioinformatics and Molecular Analysis Section.
The HLA peptide motif search algorithm was developed by Dr. Ken Parker based on binding of specific peptide sequences in the groove of HLA Class 1 molecules, in particular HLA-A2 (see, e.g., Falk et al., Nature 351: 290-6 (1991); Hunt et al., Science 255:1261-3 (1992); Parker et al., J. Immunol. 149:3580-7 (1992); Parker et al., J. Immunol. 152:163-75 (1994)). This algorithm allows location and ranking of 8-mer, 9-mer, and 10-mer peptides from a complete protein sequence for predicted binding to HLA-A2 as well as numerous other HLA Class I molecules. Many HLA class I binding peptides are 8-, 9-, 10 or 11-mers. For example, for Class I HLA-A2, the epitopes preferably contain a leucine (L) or methionine (M) at position 2 and a valine (V) or leucine (L) at the C-terminus (see, e.g., Parker et al., J. Immunol. 149:3580-7 (1992)). Selected results of 24P4C12 predicted binding peptides have been shown. The binding score corresponds to the estimated half time of dissociation of complexes containing the peptide at 37° C. at pH 6.5. Peptides with the highest binding score are predicted to be the most tightly bound to HLA Class I on the cell surface for the greatest period of time and thus represent the best immunogenic targets for T-cell recognition.
Actual binding of peptides to an HLA allele can be evaluated by stabilization of HLA expression on the antigen-processing defective cell line T2 (see, e.g., Xue et al., Prostate 30:73-8 (1997) and Peshwa et al., Prostate 36:129-38 (1998)). Immunogenicity of specific peptides can be evaluated in vitro by stimulation of CD8+ cytotoxic T lymphocytes (CTL) in the presence of antigen presenting cells such as dendritic cells.
It is to be appreciated that every epitope predicted by the BIMAS site, Epimer™ and Epimatrix™ sites, or specified by the HLA class I or class II motifs available in the art or which become part of the art such as set forth in Table IV are to be “applied” to a 24P4C12 protein in accordance with the invention. As used in this context “applied” means that a 24P4C12 protein is evaluated, e.g., visually or by computer-based patterns finding methods, as appreciated by those of skill in the relevant art. Every subsequence of a 24P4C12 protein of 8, 9, 10, or 11 amino acid residues that bears an HLA Class I motif, or a subsequence of 9 or more amino acid residues that bear an HLA Class II motif are within the scope of the invention.
III.B.) Expression of 24P4C12-Related Proteins
In an embodiment described in the examples that follow, 24P4C12 can be conveniently expressed in cells (such as 293T cells) transfected with a commercially available expression vector such as a CMV-driven expression vector encoding 24P4C12 with a C-terminal 6X His and MYC tag (pcDNA3.1/mycHIS, Invitrogen or Tag5, GenHunter Corporation, Nashville Tenn.). The Tag5 vector provides an IgGK secretion signal that can be used to facilitate the production of a secreted 24P4C12 protein in transfected cells. The secreted HIS-tagged 24P4C12 in the culture media can be purified, e.g., using a nickel column using standard techniques.
III.C.) Modifications of 24P4C12-Related Proteins
Modifications of 24P4C12-related proteins such as covalent modifications are included within the scope of this invention. One type of covalent modification includes reacting targeted amino acid residues of a 24P4C12 polypeptide with an organic derivatizing agent that is capable of reacting with selected side chains or the N- or C-terminal residues of a 24P4C12 protein. Another type of covalent modification of a 24P4C12 polypeptide included within the scope of this invention comprises altering the native glycosylation pattern of a protein of the invention. Another type of covalent modification of 24P4C12 comprises linking a 24P4C12 polypeptide to one of a variety of nonproteinaceous polymers, e.g., polyethylene glycol (PEG), polypropylene glycol, or polyoxyalkylenes, in the manner set forth in U.S. Pat. No. 4,640,835; 4,496,689; 4,301,144; 4,670,417; 4,791,192 or 4,179,337.
The 24P4C12-related proteins of the present invention can also be modified to form a chimeric molecule comprising 24P4C12 fused to another, heterologous polypeptide or amino acid sequence. Such a chimeric molecule can be synthesized chemically or recombinantly. A chimeric molecule can have a protein of the invention fused to another tumor-associated antigen or fragment thereof. Alternatively, a protein in accordance with the invention can comprise a fusion of fragments of a 24P4C12 sequence (amino or nucleic acid) such that a molecule is created that is not, through its length, directly homologous to the amino or nucleic acid sequences shown in
III.D.) Uses of 24P4C12-Related Proteins
The proteins of the invention have a number of different specific uses. As 24P4C12 is highly expressed in prostate and other cancers, 24P4C12-related proteins are used in methods that assess the status of 24P4C12 gene products in normal versus cancerous tissues, thereby elucidating the malignant phenotype. Typically, polypeptides from specific regions of a 24P4C12 protein are used to assess the presence of perturbations (such as deletions, insertions, point mutations etc.) in those regions (such as regions containing one or more motifs). Exemplary assays utilize antibodies or T cells targeting 24P4C12-related proteins comprising the amino acid residues of one or more of the biological motifs contained within a 24P4C12 polypeptide sequence in order to evaluate the characteristics of this region in normal versus cancerous tissues or to elicit an immune response to the epitope. Alternatively, 24P4C12-related proteins that contain the amino acid residues of one or more of the biological motifs in a 24P4C12 protein are used to screen for factors that interact with that region of 24P4C12.
24P4C12 protein fragments/subsequences are particularly useful in generating and characterizing domain-specific antibodies (e.g., antibodies recognizing an extracellular or intracellular epitope of a 24P4C12 protein), for identifying agents or cellular factors that bind to 24P4C12 or a particular structural domain thereof, and in various therapeutic and diagnostic contexts, including but not limited to diagnostic assays, cancer vaccines and methods of preparing such vaccines.
Proteins encoded by the 24P4C12 genes, or by analogs, homologs or fragments thereof, have a variety of uses, including but not limited to generating antibodies and in methods for identifying ligands and other agents and cellular constituents that bind to a 24P4C12 gene product. Antibodies raised against a 24P4C12 protein or fragment thereof are useful in diagnostic and prognostic assays, and imaging methodologies in the management of human cancers characterized by expression of 24P4C12 protein, such as those listed in Table I. Such antibodies can be expressed intracellularly and used in methods of treating patients with such cancers. 24P4C12-related nucleic acids or proteins are also used in generating HTL or CTL responses.
Various immunological assays useful for the detection of 24P4C12 proteins are used, including but not limited to various types of radioimmunoassays, enzyme-linked immunosorbent assays (ELISA), enzyme-linked immunofluorescent assays (ELIFA), immunocytochemical methods, and the like. Antibodies can be labeled and used as immunological imaging reagents capable of detecting 24P4C12-expressing cells (e.g., in radioscintigraphic imaging methods). 24P4C12 proteins are also particularly useful in generating cancer vaccines, as further described herein.
IV.) 24P4C12 Antibodies
Another aspect of the invention provides antibodies that bind to 24P4C12-related proteins (See
24P4C12 antibodies of the invention are particularly useful in cancer (see, e.g., Table I) diagnostic and prognostic assays, and imaging methodologies. Similarly, such antibodies are useful in the treatment, diagnosis, and/or prognosis of colon and other cancers, to the extent 24P4C12 is also expressed or overexpressed in these other cancers. Moreover, intracellularly expressed antibodies (e.g., single chain antibodies) are therapeutically useful in treating cancers in which the expression of 24P4C12 is involved, such as advanced or metastatic colon cancers or other advanced or metastatic cancers.
The invention also provides various immunological assays useful for the detection and quantification of 24P4C12 and variant 24P4C12-related proteins. Such assays can comprise one or more 24P4C12 antibodies capable of recognizing and binding a 24P4C12-related protein, as appropriate. These assays are performed within various immunological assay formats well known in the art, including but not limited to various types of radioimmunoassays, enzyme-linked immunosorbent assays (ELISA), enzyme-linked immunofluorescent assays (ELIFA), and the like.
Immunological non-antibody assays of the invention also comprise T cell immunogenicity assays (inhibitory or stimulatory) as well as major histocompatibility complex (MHC) binding assays.
In addition, immunological imaging methods capable of detecting prostate or colon cancer and other cancers expressing 24P4C12 are also provided by the invention, including but not limited to radioscintigraphic imaging methods using labeled 24P4C12 MAbs. Such assays are clinically useful in the detection, monitoring, and prognosis of 24P4C12 expressing cancers such as colon cancer.
24P4C12 antibodies are also used in methods for purifying a 24P4C12-related protein and for isolating 24P4C12 homologues and related molecules. For example, a method of purifying a 24P4C12-related protein comprises incubating a 24P4C12 antibody, which has been coupled to a solid matrix, with a lysate or other solution containing a 24P4C12-related protein under conditions that permit the 24P4C12 antibody to bind to the 24P4C12-related protein; washing the solid matrix to eliminate impurities; and eluting the 24P4C12-related protein from the coupled antibody. Other uses of 24P4C12 antibodies in accordance with the invention include generating anti-idiotypic antibodies that mimic a 24P4C12 protein.
Various methods for the preparation of antibodies are well known in the art. For example, antibodies can be prepared by immunizing a suitable mammalian host using a 24P4C12-related protein, peptide, or fragment, in isolated or immunoconjugated form (Antibodies: A Laboratory Manual, CSH Press, Eds., Harlow, and Lane (1988); Harlow, Antibodies, Cold Spring Harbor Press, NY (1989)). In addition, fusion proteins of 24P4C12 can also be used, such as a 24P4C12 GST-fusion protein. In a particular embodiment, a GST fusion protein comprising all or most of the amino acid sequence of
In addition, naked DNA immunization techniques known in the art are used (with or without purified 24P4C12-related protein or 24P4C12 expressing cells) to generate an immune response to the encoded immunogen (for review, see Donnelly et al., 1997, Ann. Rev. Immunol. 15: 617-648).
The amino acid sequence of a 24P4C12 protein as shown in
24P4C12 monoclonal antibodies can be produced by various means well known in the art. For example, immortalized cell lines that secrete a desired monoclonal antibody are prepared using the standard hybridoma technology of Kohler and Milstein or modifications that immortalize antibody-producing B cells, as is generally known. Immortalized cell lines that secrete the desired antibodies are screened by immunoassay in which the antigen is a 24P4C12-related protein. When the appropriate immortalized cell culture is identified, the cells can be expanded and antibodies produced either from in vitro cultures or from ascites fluid.
The antibodies or fragments of the invention can also be produced, by recombinant means. Regions that bind specifically to the desired regions of a 24P4C12 protein can also be produced in the context of chimeric or complementarity-determining region (CDR) grafted antibodies of multiple species origin. Humanized or human 24P4C12 antibodies can also be produced, and are preferred for use in therapeutic contexts. Methods for humanizing murine and other non-human antibodies, by substituting one or more of the non-human antibody CDRs for corresponding human antibody sequences, are well known (see for example, Jones et al., 1986, Nature 321: 522-525; Riechmann et al., 1988, Nature 332: 323-327; Verhoeyen et al., 1988, Science 239: 1534-1536). See also, Carter et al., 1993, Proc. Natl. Acad. Sci. USA 89: 4285 and Sims et al., 1993, J. Immunol. 151: 2296.
In a preferred embodiment, the antibodies of the present invention comprise fully human 24P4C12 antibodies (24P4C12 MAbs). Various methods in the art provide means for producing fully human 24P4C12 MAbs. For example, a preferred embodiment provides for techniques using transgenic mice, inactivated for antibody production, engineered with human heavy and light chains loci referred to as Xenomouse (Amgen Fremont, Inc.). An exemplary description of preparing transgenic mice that produce human antibodies can be found in U.S. Pat. No. 6,657,103. See, also, U.S. Pat. Nos. 5,569,825; 5,625,126; 5,633,425; 5,661,016; and 5,545,806; and Mendez, et. al. Nature Genetics, 15: 146-156 (1998); Kellerman, S. A. & Green, L. L., Curr. Opin. Biotechnol 13, 593-597 (2002).
In addition, human antibodies of the invention can be generated using the HuMAb mouse (Medarex, Inc.) which contains human immunoglobulin gene miniloci that encode unrearranged human heavy (mu and gamma) and kappa light chain immunoglobulin sequences, together with targeted mutations that inactivate the endogenous mu and kappa chain loci (see e.g., Lonberg, et al. (1994) Nature 368(6474): 856-859).
In another embodiment, fully human antibodies of the invention can be raised using a mouse that carries human immunoglobulin sequences on transgenes and transchromosomes, such as a mouse that carries a human heavy chain transgene and a human light chain transchromosome. Such mice, referred to herein as “KM mice”, such mice are described in Tomizuka et al. (2000) Proc. Natl. Acad. Sci. USA 97:722-727 and PCT Publication WO 02/43478 to Tomizuka, et al.
Human monoclonal antibodies of the invention can also be prepared using phage display methods for screening libraries of human immunoglobulin genes. Such phage display methods for isolating human antibodies are established in the art. See for example: U.S. Pat. Nos. 5,223,409; 5,403,484; and 5,571,698 to Ladner et al.; U.S. Pat. Nos. 5,427,908 and 5,580,717 to Dower et al.; U.S. Pat. Nos. 5,969,108 and 6,172,197 to McCafferty et al.; and U.S. Pat. Nos. 5,885,793; 6,521,404; 6,544,731; 6,555,313; 6,582,915 and 6,593,081 to Griffiths et al.
Human monoclonal antibodies of the invention can also be prepared using SCID mice into which human immune cells have been reconstituted such that a human antibody response can be generated upon immunization. Such mice are described in, for example, U.S. Pat. Nos. 5,476,996 and 5,698,767 to Wilson et al.
In yet another embodiment, an 24P4C12 MAbs of the invention comprises heavy and light chain variable regions comprising amino acid sequences that are homologous to the amino acid sequences of the preferred antibodies described herein (See,
For example, the invention provides an isolated monoclonal antibody, or antigen binding portion thereof, comprising a heavy chain variable region and a light chain variable region, wherein:
(a) the heavy chain variable region comprises an amino acid sequence that is at least 80% homologous to an amino acid sequence set forth in
(b) the light chain variable region comprises an amino acid sequence that is at least 80% homologous to an amino acid sequence set forth in
In other embodiments, the VH and/or VL amino acid sequences may be 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% homologous to the sequences set forth in
Engineered antibodies of the invention include those in which modifications have been made to framework residues within VH and/or VL (e.g. to improve the properties of the antibody). Typically such framework modifications are made to decrease the immunogenicity of the antibody. For example, one approach is to “backmutate” one or more framework residues to the corresponding germline sequence. More specifically, an antibody that has undergone somatic mutation may contain framework residues that differ from the germline sequence from which the antibody is derived. Such residues can be identified by comparing the antibody framework sequences to the germline sequences from which the antibody is derived. To return the framework region sequences to their germline configuration, the somatic mutations can be “backmutated” to the germline sequence by, for example, site-directed mutagenesis or PCR-mediated mutagenesis (e.g., “backmutated” from leucine to methionine). Such “backmutated” antibodies are also intended to be encompassed by the invention.
Another type of framework modification involves mutating one or more residues within the framework region, or even within one or more CDR regions, to remove T-cell epitopes to thereby reduce the potential immunogenicity of the antibody. This approach is also referred to as “deimmunization” and is described in further detail in U.S. Patent Publication No. 2003/0153043 by Carr et al.
In addition or alternative to modifications made within the framework or CDR regions, antibodies of the invention may be engineered to include modifications within the Fc region, typically to alter one or more functional properties of the antibody, such as serum half-life, complement fixation, Fc receptor binding, and/or antigen-dependent cellular cytotoxicity. Furthermore, a 24P4C12 MAb of the invention may be chemically modified (e.g., one or more chemical moieties can be attached to the antibody) or be modified to alter its glycosylation, again to alter one or more functional properties of the MAb. Each of these embodiments is described in further detail below.
In one embodiment, the hinge region of CH1 is modified such that the number of cysteine residues in the hinge region is altered, e.g., increased or decreased. This approach is described further in U.S. Pat. No. 5,677,425 by Bodmer et al. The number of cysteine residues in the hinge region of CH1 is altered to, for example, facilitate assembly of the light and heavy chains or to increase or decrease the stability of the 24P4C12 MAb.
In another embodiment, the Fc hinge region of an antibody is mutated to decrease the biological half life of the 24P4C12 MAb. More specifically, one or more amino acid mutations are introduced into the CH2-CH3 domain interface region of the Fc-hinge fragment such that the antibody has impaired Staphylococcyl protein A (SpA) binding relative to native Fc-hinge domain SpA binding. This approach is described in further detail in U.S. Pat. No. 6,165,745 by Ward et al.
In another embodiment, the 24P4C12 MAb is modified to increase its biological half life. Various approaches are possible. For example, mutations can be introduced as described in U.S. Pat. No. 6,277,375 to Ward. Alternatively, to increase the biological half life, the antibody can be altered within the CH1 or CL region to contain a salvage receptor binding epitope taken from two loops of a CH2 domain of an Fc region of an IgG, as described in U.S. Pat. Nos. 5,869,046 and 6,121,022 by Presta et al.
In yet other embodiments, the Fc region is altered by replacing at least one amino acid residue with a different amino acid residue to alter the effector function(s) of the 24P4C12 MAb. For example, one or more amino acids selected from amino acid specific residues can be replaced with a different amino acid residue such that the antibody has an altered affinity for an effector ligand but retains the antigen-binding ability of the parent antibody. The effector ligand to which affinity is altered can be, for example, an Fc receptor or the C1 component of complement. This approach is described in further detail in U.S. Pat. Nos. 5,624,821 and 5,648,260, both by Winter et al.
Reactivity of 24P4C12 antibodies with a 24P4C12-related protein can be established by a number of well known means, including Western blot, immunoprecipitation, ELISA, and FACS analyses using, as appropriate, 24P4C12-related proteins, 24P4C12-expressing cells or extracts thereof. A 24P4C12 antibody or fragment thereof can be labeled with a detectable marker or conjugated to a second molecule. Suitable detectable markers include, but are not limited to, a radioisotope, a fluorescent compound, a bioluminescent compound, chemiluminescent compound, a metal chelator or an enzyme. Further, bi-specific antibodies specific for two or more 24P4C12 epitopes are generated using methods generally known in the art. Homodimeric antibodies can also be generated by cross-linking techniques known in the art (e.g., Wolff et al., Cancer Res. 53: 2560-2565).
The antibodies designated Ha5-1(5)1, Ha5-1(5)2.1, Ha5-3(1,4)7.1, Ha5-7acd10.1, Ha5-7acd16.1, and Ha5-11b1.1 were sent (via Federal Express) to the American Type Culture Collection (ATCC), P.O. Box 1549, Manassas, Va. 20108 on 8 Aug. 2007 and assigned Accession numbers PTA-8598, PTA-8602, PTA-8597, PTA-8601, PTA-8600, PTA-8599, respectively.
IV.A.) 24P4C12 Cellular Immune Responses
The mechanism by which T cells recognize antigens has been delineated. Efficacious peptide epitope vaccine compositions of the invention induce therapeutic or prophylactic immune responses in very broad segments of the world-wide population. For an understanding of the value and efficacy of compositions of the invention that induce cellular immune responses, a brief review of immunology-related technology is provided.
A complex of an HLA molecule and a peptidic antigen acts as the ligand recognized by HLA-restricted T cells (Buus, S. et al., Cell 47:1071, 1986; Babbitt, B. P. et al., Nature 317:359, 1985; Townsend, A. and Bodmer, H., Annu. Rev. Immunol. 7:601, 1989; Germain, R. N., Annu. Rev. Immunol. 11:403, 1993). Through the study of single amino acid substituted antigen analogs and the sequencing of endogenously bound, naturally processed peptides, critical residues that correspond to motifs required for specific binding to HLA antigen molecules have been identified and are set forth in Table IV (see also, e.g., Southwood, et al., J. Immunol. 160:3363, 1998; Rammensee, et al., Immunogenetics 41:178, 1995; Rammensee et al., SYFPEITHI, access via World Wide Web at URL (126.96.36.199/scripts.hlaserver.dll/home.htm); Sette, A. and Sidney, J. Curr. Opin. Immunol. 10:478, 1998; Engelhard, V. H., Curr. Opin. Immunol. 6:13, 1994; Sette, A. and Grey, H. M., Curr. Opin. Immunol. 4:79, 1992; Sinigaglia, F. and Hammer, J. Curr. Biol. 6:52, 1994; Ruppert et al., Cell 74:929-937, 1993; Kondo et al., J. Immunol. 155:4307-4312, 1995; Sidney et al., J. Immunol. 157:3480-3490, 1996; Sidney et al., Human Immunol. 45:79-93, 1996; Sette, A. and Sidney, J. Immunogenetics 1999 November; 50(3-4):201-12, Review).
Furthermore, x-ray crystallographic analyses of HLA-peptide complexes have revealed pockets within the peptide binding cleft/groove of HLA molecules which accommodate, in an allele-specific mode, residues borne by peptide ligands; these residues in turn determine the HLA binding capacity of the peptides in which they are present. (See, e.g., Madden, D. R. Annu. Rev. Immunol. 13:587, 1995; Smith, et al., Immunity 4:203, 1996; Fremont et al., Immunity 8:305, 1998; Stern et al., Structure 2:245, 1994; Jones, E. Y. Curr. Opin. Immunol. 9:75, 1997; Brown, J. H. et al., Nature 364:33, 1993; Guo, H. C. et al., Proc. Natl. Acad. Sci. USA 90:8053, 1993; Guo, H. C. et al., Nature 360:364, 1992; Silver, M. L. et al., Nature 360:367, 1992; Matsumura, M. et al., Science 257:927, 1992; Madden et al., Cell 70:1035, 1992; Fremont, D. H. et al., Science 257:919, 1992; Saper, M. A., Bjorkman, P. J. and Wiley, D. C., J. Mol. Biol. 219:277, 1991.)
Accordingly, the definition of class I and class II allele-specific HLA binding motifs, or class I or class II supermotifs allows identification of regions within a protein that are correlated with binding to particular HLA antigen(s).
Thus, by a process of HLA motif identification, candidates for epitope-based vaccines have been identified; such candidates can be further evaluated by HLA-peptide binding assays to determine binding affinity and/or the time period of association of the epitope and its corresponding HLA molecule. Additional confirmatory work can be performed to select, amongst these vaccine candidates, epitopes with preferred characteristics in terms of population coverage, and/or immunogenicity.
Various strategies can be utilized to evaluate cellular immunogenicity, including:
1) Evaluation of primary T cell cultures from normal individuals (see, e.g., Wentworth, P. A. et al., Mol. Immunol. 32:603, 1995; Celis, E. et al., Proc. Natl. Acad. Sci. USA 91:2105, 1994; Tsai, V. et al., J. Immunol. 158:1796, 1997; Kawashima, I. et al., Human Immunol. 59:1, 1998). This procedure involves the stimulation of peripheral blood lymphocytes (PBL) from normal subjects with a test peptide in the presence of antigen presenting cells in vitro over a period of several weeks. T cells specific for the peptide become activated during this time and are detected using, e.g., a lymphokine- or 51Cr-release assay involving peptide sensitized target cells.
2) Immunization of HLA transgenic mice (see, e.g., Wentworth, P. A. et al., J. Immunol. 26:97, 1996; Wentworth, P. A. et al., Int. Immunol. 8:651, 1996; Alexander, J. et al., J. Immunol. 159:4753, 1997). For example, in such methods peptides in incomplete Freund's adjuvant are administered subcutaneously to HLA transgenic mice. Several weeks following immunization, splenocytes are removed and cultured in vitro in the presence of test peptide for approximately one week. Peptide-specific T cells are detected using, e.g., a 51Cr-release assay involving peptide sensitized target cells and target cells expressing endogenously generated antigen.
3) Demonstration of recall T cell responses from immune individuals who have been either effectively vaccinated and/or from chronically ill patients (see, e.g., Rehermann, B. et al., J. Exp. Med. 181:1047, 1995; Doolan, D. L. et al., Immunity 7:97, 1997; Bertoni, R. et al., J. Clin. Invest. 100:503, 1997; Threlkeld, S. C. et al., J. Immunol. 159:1648, 1997; Diepolder, H. M. et al., J. Virol. 71:6011, 1997). Accordingly, recall responses are detected by culturing PBL from subjects that have been exposed to the antigen due to disease and thus have generated an immune response “naturally”, or from patients who were vaccinated against the antigen. PBL from subjects are cultured in vitro for 1-2 weeks in the presence of test peptide plus antigen presenting cells (APC) to allow activation of “memory” T cells, as compared to “naive” T cells. At the end of the culture period, T cell activity is detected using assays including 51Cr release involving peptide-sensitized targets, T cell proliferation, or lymphokine release.
V.) 24P4C12 Transgenic Animals
Nucleic acids that encode a 24P4C12-related protein can also be used to generate either transgenic animals or “knock out” animals that, in turn, are useful in the development and screening of therapeutically useful reagents. In accordance with established techniques, cDNA encoding 24P4C12 can be used to clone genomic DNA that encodes 24P4C12. The cloned genomic sequences can then be used to generate transgenic animals containing cells that express DNA that encode 24P4C12. Methods for generating transgenic animals, particularly animals such as mice or rats, have become conventional in the art and are described, for example, in U.S. Pat. No. 4,736,866 issued 12 Apr. 1988, and U.S. Pat. No. 4,870,009 issued 26 Sep. 1989. Typically, particular cells would be targeted for 24P4C12 transgene incorporation with tissue-specific enhancers.
Transgenic animals that include a copy of a transgene encoding 24P4C12 can be used to examine the effect of increased expression of DNA that encodes 24P4C12. Such animals can be used as tester animals for reagents thought to confer protection from, for example, pathological conditions associated with its overexpression. In accordance with this aspect of the invention, an animal is treated with a reagent and a reduced incidence of a pathological condition, compared to untreated animals that bear the transgene, would indicate a potential therapeutic intervention for the pathological condition.
Alternatively, non-human homologues of 24P4C12 can be used to construct a 24P4C12 “knock out” animal that has a defective or altered gene encoding 24P4C12 as a result of homologous recombination between the endogenous gene encoding 24P4C12 and altered genomic DNA encoding 24P4C12 introduced into an embryonic cell of the animal. For example, cDNA that encodes 24P4C12 can be used to clone genomic DNA encoding 24P4C12 in accordance with established techniques. A portion of the genomic DNA encoding 24P4C12 can be deleted or replaced with another gene, such as a gene encoding a selectable marker that can be used to monitor integration. Typically, several kilobases of unaltered flanking DNA (both at the 5′ and 3′ ends) are included in the vector (see, e.g., Thomas and Capecchi, Cell, 51:503 (1987) for a description of homologous recombination vectors). The vector is introduced into an embryonic stem cell line (e.g., by electroporation) and cells in which the introduced DNA has homologously recombined with the endogenous DNA are selected (see, e.g., Li et al., Cell, 69:915 (1992)). The selected cells are then injected into a blastocyst of an animal (e.g., a mouse or rat) to form aggregation chimeras (see, e.g., Bradley, in Teratocarcinomas and Embryonic Stem Cells: A Practical Approach, E. J. Robertson, ed. (IRL, Oxford, 1987), pp. 113-152). A chimeric embryo can then be implanted into a suitable pseudopregnant female foster animal, and the embryo brought to term to create a “knock out” animal. Progeny harboring the homologously recombined DNA in their germ cells can be identified by standard techniques and used to breed animals in which all cells of the animal contain the homologously recombined DNA. Knock out animals can be characterized, for example, for their ability to defend against certain pathological conditions or for their development of pathological conditions due to absence of a 24P4C12 polypeptide.
VI.) Methods for the Detection of 24P4C12
Another aspect of the present invention relates to methods for detecting 24P4C12 polynucleotides and 24P4C12-related proteins, as well as methods for identifying a cell that expresses 24P4C12. The expression profile of 24P4C12 makes it a diagnostic marker for metastasized disease. Accordingly, the status of 24P4C12 gene products provides information useful for predicting a variety of factors including susceptibility to advanced stage disease, rate of progression, and/or tumor aggressiveness. As discussed in detail herein, the status of 24P4C12 gene products in patient samples can be analyzed by a variety protocols that are well known in the art including immunohistochemical analysis, the variety of Northern blotting techniques including in situ hybridization, RT-PCR analysis (for example on laser capture micro-dissected samples), Western blot analysis and tissue array analysis.
More particularly, the invention provides assays for the detection of 24P4C12 polynucleotides in a biological sample, such as serum, bone, prostate, and other tissues, urine, semen, cell preparations, and the like. Detectable 24P4C12 polynucleotides include, for example, a 24P4C12 gene or fragment thereof, 24P4C12 mRNA, alternative splice variant 24P4C12 mRNAs, and recombinant DNA or RNA molecules that contain a 24P4C12 polynucleotide. A number of methods for amplifying and/or detecting the presence of 24P4C12 polynucleotides are well known in the art and can be employed in the practice of this aspect of the invention.
In one embodiment, a method for detecting a 24P4C12 mRNA in a biological sample comprises producing cDNA from the sample by reverse transcription using at least one primer; amplifying the cDNA so produced using a 24P4C12 polynucleotides as sense and antisense primers to amplify 24P4C12 cDNAs therein; and detecting the presence of the amplified 24P4C12 cDNA. Optionally, the sequence of the amplified 24P4C12 cDNA can be determined.
In another embodiment, a method of detecting a 24P4C12 gene in a biological sample comprises first isolating genomic DNA from the sample; amplifying the isolated genomic DNA using 24P4C12 polynucleotides as sense and antisense primers; and detecting the presence of the amplified 24P4C12 gene. Any number of appropriate sense and antisense probe combinations can be designed from a 24P4C12 nucleotide sequence (see, e.g.,
The invention also provides assays for detecting the presence of a 24P4C12 protein in a tissue or other biological sample such as serum, semen, bone, prostate, urine, cell preparations, and the like. Methods for detecting a 24P4C12-related protein are also well known and include, for example, immunoprecipitation, immunohistochemical analysis, Western blot analysis, molecular binding assays, ELISA, ELIFA and the like. For example, a method of detecting the presence of a 24P4C12-related protein in a biological sample comprises first contacting the sample with a 24P4C12 antibody, a 24P4C12-reactive fragment thereof, or a recombinant protein containing an antigen-binding region of a 24P4C12 antibody; and then detecting the binding of 24P4C12-related protein in the sample.
Methods for identifying a cell that expresses 24P4C12 are also within the scope of the invention. In one embodiment, an assay for identifying a cell that expresses a 24P4C12 gene comprises detecting the presence of 24P4C12 mRNA in the cell. Methods for the detection of particular mRNAs in cells are well known and include, for example, hybridization assays using complementary DNA probes (such as in situ hybridization using labeled 24P4C12 riboprobes, Northern blot and related techniques) and various nucleic acid amplification assays (such as RT-PCR using complementary primers specific for 24P4C12, and other amplification type detection methods, such as, for example, branched DNA, SISBA, TMA and the like). Alternatively, an assay for identifying a cell that expresses a 24P4C12 gene comprises detecting the presence of 24P4C12-related protein in the cell or secreted by the cell. Various methods for the detection of proteins are well known in the art and are employed for the detection of 24P4C12-related proteins and cells that express 24P4C12-related proteins.
24P4C12 expression analysis is also useful as a tool for identifying and evaluating agents that modulate 24P4C12 gene expression. For example, 24P4C12 expression is significantly upregulated in ovarian cancer, and is expressed in cancers of the tissues listed in Table I. Identification of a molecule or biological agent that inhibits 24P4C12 expression or over-expression in cancer cells is of therapeutic value. For example, such an agent can be identified by using a screen that quantifies 24P4C12 expression by RT-PCR, nucleic acid hybridization or antibody binding.
VII.) Methods for Monitoring the Status of 24P4C12-Related Genes and Their Products
Oncogenesis is known to be a multistep process where cellular growth becomes progressively dysregulated and cells progress from a normal physiological state to precancerous and then cancerous states (see, e.g., Alers et al., Lab Invest. 77(5): 437-438 (1997) and Isaacs et al., Cancer Surv. 23: 19-32 (1995)). In this context, examining a biological sample for evidence of dysregulated cell growth (such as aberrant 24P4C12 expression in cancers) allows for early detection of such aberrant physiology, before a pathologic state such as cancer has progressed to a stage that therapeutic options are more limited and or the prognosis is worse. In such examinations, the status of 24P4C12 in a biological sample of interest can be compared, for example, to the status of 24P4C12 in a corresponding normal sample (e.g. a sample from that individual or alternatively another individual that is not affected by a pathology). An alteration in the status of 24P4C12 in the biological sample (as compared to the normal sample) provides evidence of dysregulated cellular growth. In addition to using a biological sample that is not affected by a pathology as a normal sample, one can also use a predetermined normative value such as a predetermined normal level of mRNA expression (see, e.g., Grever et al., J. Comp. Neurol. 1996 Dec. 9; 376(2): 306-14 and U.S. Pat. No. 5,837,501) to compare 24P4C12 status in a sample.
The term “status” in this context is used according to its art accepted meaning and refers to the condition or state of a gene and its products. Typically, skilled artisans use a number of parameters to evaluate the condition or state of a gene and its products. These include, but are not limited to the location of expressed gene products (including the location of 24P4C12 expressing cells) as well as the level, and biological activity of expressed gene products (such as 24P4C12 mRNA, polynucleotides and polypeptides). Typically, an alteration in the status of 24P4C12 comprises a change in the location of 24P4C12 and/or 24P4C12 expressing cells and/or an increase in 24P4C12 mRNA and/or protein expression.
24P4C12 status in a sample can be analyzed by a number of means well known in the art, including without limitation, immunohistochemical analysis, in situ hybridization, RT-PCR analysis on laser capture micro-dissected samples, Western blot analysis, and tissue array analysis. Typical protocols for evaluating the status of a 24P4C12 gene and gene products are found, for example in Ausubel et al. eds., 1995, Current Protocols In Molecular Biology, Units 2 (Northern Blotting), 4 (Southern Blotting), 15 (Immunoblotting) and 18 (PCR Analysis). Thus, the status of 24P4C12 in a biological sample is evaluated by various methods utilized by skilled artisans including, but not limited to genomic Southern analysis (to examine, for example perturbations in a 24P4C12 gene), Northern analysis and/or PCR analysis of 24P4C12 mRNA (to examine, for example alterations in the polynucleotide sequences or expression levels of 24P4C12 mRNAs), and, Western and/or immunohistochemical analysis (to examine, for example alterations in polypeptide sequences, alterations in polypeptide localization within a sample, alterations in expression levels of 24P4C12 proteins and/or associations of 24P4C12 proteins with polypeptide binding partners). Detectable 24P4C12 polynucleotides include, for example, a 24P4C12 gene or fragment thereof, 24P4C12 mRNA, alternative splice variants, 24P4C12 mRNAs, and recombinant DNA or RNA molecules containing a 24P4C12 polynucleotide.
The expression profile of 24P4C12 makes it a diagnostic marker for local and/or metastasized disease, and provides information on the growth or oncogenic potential of a biological sample. In particular, the status of 24P4C12 provides information useful for predicting susceptibility to particular disease stages, progression, and/or tumor aggressiveness. The invention provides methods and assays for determining 24P4C12 status and diagnosing cancers that express 24P4C12, such as cancers of the tissues listed in Table I. For example, because 24P4C12 mRNA is so highly expressed in kidney and other cancers relative to normal kidney tissue, assays that evaluate the levels of 24P4C12 mRNA transcripts or proteins in a biological sample can be used to diagnose a disease associated with 24P4C12 dysregulation, and can provide prognostic information useful in defining appropriate therapeutic options.
The expression status of 24P4C12 provides information including the presence, stage and location of dysplastic, precancerous and cancerous cells, predicting susceptibility to various stages of disease, and/or for gauging tumor aggressiveness. Moreover, the expression profile makes it useful as an imaging reagent for metastasized disease. Consequently, an aspect of the invention is directed to the various molecular prognostic and diagnostic methods for examining the status of 24P4C12 in biological samples such as those from individuals suffering from, or suspected of suffering from a pathology characterized by dysregulated cellular growth, such as cancer.
As described above, the status of 24P4C12 in a biological sample can be examined by a number of well-known procedures in the art. For example, the status of 24P4C12 in a biological sample taken from a specific location in the body can be examined by evaluating the sample for the presence or absence of 24P4C12 expressing cells (e.g. those that express 24P4C12 mRNAs or proteins). This examination can provide evidence of dysregulated cellular growth, for example, when 24P4C12-expressing cells are found in a biological sample that does not normally contain such cells (such as a lymph node), because such alterations in the status of 24P4C12 in a biological sample are often associated with dysregulated cellular growth. Specifically, one indicator of dysregulated cellular growth is the metastases of cancer cells from an organ of origin (such as the prostate) to a different area of the body (such as a lymph node). In this context, evidence of dysregulated cellular growth is important for example because occult lymph node metastases can be detected in a substantial proportion of patients with prostate cancer, and such metastases are associated with known predictors of disease progression (see, e.g., Murphy et al., Prostate 42(4): 315-317 (2000); Su et al., Semin. Surg. Oncol. 18(1): 17-28 (2000) and Freeman et al., J Urol 1995 August 154(2 Pt 1):474-8).
In one aspect, the invention provides methods for monitoring 24P4C12 gene products by determining the status of 24P4C12 gene products expressed by cells from an individual suspected of having a disease associated with dysregulated cell growth (such as hyperplasia or cancer) and then comparing the status so determined to the status of 24P4C12 gene products in a corresponding normal sample. The presence of aberrant 24P4C12 gene products in the test sample relative to the normal sample provides an indication of the presence of dysregulated cell growth within the cells of the individual.
In another aspect, the invention provides assays useful in determining the presence of cancer in an individual, comprising detecting a significant increase in 24P4C12 mRNA or protein expression in a test cell or tissue sample relative to expression levels in the corresponding normal cell or tissue. The presence of 24P4C12 mRNA can, for example, be evaluated in tissues including but not limited to those listed in Table I. The presence of significant 24P4C12 expression in any of these tissues is useful to indicate the emergence, presence and/or severity of a cancer, since the corresponding normal tissues do not express 24P4C12 mRNA or express it at lower levels.
In a related embodiment, 24P4C12 status is determined at the protein level rather than at the nucleic acid level. For example, such a method comprises determining the level of 24P4C12 protein expressed by cells in a test tissue sample and comparing the level so determined to the level of 24P4C12 expressed in a corresponding normal sample. In one embodiment, the presence of 24P4C12 protein is evaluated, for example, using immunohistochemical methods. 24P4C12 antibodies or binding partners capable of detecting 24P4C12 protein expression are used in a variety of assay formats well known in the art for this purpose.
In a further embodiment, one can evaluate the status of 24P4C12 nucleotide and amino acid sequences in a biological sample in order to identify perturbations in the structure of these molecules. These perturbations can include insertions, deletions, substitutions and the like. Such evaluations are useful because perturbations in the nucleotide and amino acid sequences are observed in a large number of proteins associated with a growth dysregulated phenotype (see, e.g., Marrogi et al., 1999, J. Cutan. Pathol. 26(8):369-378). For example, a mutation in the sequence of 24P4C12 may be indicative of the presence or promotion of a tumor. Such assays therefore have diagnostic and predictive value where a mutation in 24P4C12 indicates a potential loss of function or increase in tumor growth.
A wide variety of assays for observing perturbations in nucleotide and amino acid sequences are well known in the art. For example, the size and structure of nucleic acid or amino acid sequences of 24P4C12 gene products are observed by the Northern, Southern, Western, PCR and DNA sequencing protocols discussed herein. In addition, other methods for observing perturbations in nucleotide and amino acid sequences such as single strand conformation polymorphism analysis are well known in the art (see, e.g., U.S. Pat. No. 5,382,510 issued 7 Sep. 1999, and U.S. Pat. No. 5,952,170 issued 17 Jan. 1995).
Additionally, one can examine the methylation status of a 24P4C12 gene in a biological sample. Aberrant demethylation and/or hypermethylation of CpG islands in gene 5′ regulatory regions frequently occurs in immortalized and transformed cells, and can result in altered expression of various genes. For example, promoter hypermethylation of the pi-class glutathione S-transferase (a protein expressed in normal prostate but not expressed in >90% of prostate carcinomas) appears to permanently silence transcription of this gene and is the most frequently detected genomic alteration in prostate carcinomas (De Marzo et al., Am. J. Pathol. 155(6): 1985-1992 (1999)). In addition, this alteration is present in at least 70% of cases of high-grade prostatic intraepithelial neoplasia (PIN) (Brooks et al., Cancer Epidemiol. Biomarkers Prev., 1998, 7:531-536). In another example, expression of the LAGE-I tumor specific gene (which is not expressed in normal prostate but is expressed in 25-50% of prostate cancers) is induced by deoxy-azacytidine in lymphoblastoid cells, suggesting that tumoral expression is due to demethylation (Lethe et al., Int. J. Cancer 76(6): 903-908 (1998)). A variety of assays for examining methylation status of a gene are well known in the art. For example, one can utilize, in Southern hybridization approaches, methylation-sensitive restriction enzymes that cannot cleave sequences that contain methylated CpG sites to assess the methylation status of CpG islands. In addition, MSP (methylation specific PCR) can rapidly profile the methylation status of all the CpG sites present in a CpG island of a given gene. This procedure involves initial modification of DNA by sodium bisulfite (which will convert all unmethylated cytosines to uracil) followed by amplification using primers specific for methylated versus unmethylated DNA. Protocols involving methylation interference can also be found for example in Current Protocols In Molecular Biology, Unit 12, Frederick M. Ausubel et al. eds., 1995.
Gene amplification is an additional method for assessing the status of 24P4C12. Gene amplification is measured in a sample directly, for example, by conventional Southern blotting or Northern blotting to quantitate the transcription of mRNA (Thomas, 1980, Proc. Natl. Acad. Sci. USA, 77:5201 5205), dot blotting (DNA analysis), or in situ hybridization, using an appropriately labeled probe, based on the sequences provided herein. Alternatively, antibodies are employed that recognize specific duplexes, including DNA duplexes, RNA duplexes, and DNA RNA hybrid duplexes or DNA protein duplexes. The antibodies in turn are labeled and the assay carried out where the duplex is bound to a surface, so that upon the formation of duplex on the surface, the presence of antibody bound to the duplex can be detected.
Biopsied tissue or peripheral blood can be conveniently assayed for the presence of cancer cells using for example, Northern, dot blot or RT-PCR analysis to detect 24P4C12 expression. The presence of RT-PCR amplifiable 24P4C12 mRNA provides an indication of the presence of cancer. RT-PCR assays are well known in the art. RT-PCR detection assays for tumor cells in peripheral blood are currently being evaluated for use in the diagnosis and management of a number of human solid tumors. In the prostate cancer field, these include RT-PCR assays for the detection of cells expressing PSA and PSM (Verkaik et al., 1997, Urol. Res. 25:373-384; Ghossein et al., 1995, J. Clin. Oncol. 13:1195-2000; Heston et al., 1995, Clin. Chem. 41:1687-1688).
A further aspect of the invention is an assessment of the susceptibility that an individual has for developing cancer. In one embodiment, a method for predicting susceptibility to cancer comprises detecting 24P4C12 mRNA or 24P4C12 protein in a tissue sample, its presence indicating susceptibility to cancer, wherein the degree of 24P4C12 mRNA expression correlates to the degree of susceptibility. In a specific embodiment, the presence of 24P4C12 in prostate or other tissue is examined, with the presence of 24P4C12 in the sample providing an indication of prostate cancer susceptibility (or the emergence or existence of a prostate tumor). Similarly, one can evaluate the integrity 24P4C12 nucleotide and amino acid sequences in a biological sample, in order to identify perturbations in the structure of these molecules such as insertions, deletions, substitutions and the like. The presence of one or more perturbations in 24P4C12 gene products in the sample is an indication of cancer susceptibility (or the emergence or existence of a tumor).
The invention also comprises methods for gauging tumor aggressiveness. In one embodiment, a method for gauging aggressiveness of a tumor comprises determining the level of 24P4C12 mRNA or 24P4C12 protein expressed by tumor cells, comparing the level so determined to the level of 24P4C12 mRNA or 24P4C12 protein expressed in a corresponding normal tissue taken from the same individual or a normal tissue reference sample, wherein the degree of 24P4C12 mRNA or 24P4C12 protein expression in the tumor sample relative to the normal sample indicates the degree of aggressiveness. In a specific embodiment, aggressiveness of a tumor is evaluated by determining the extent to which 24P4C12 is expressed in the tumor cells, with higher expression levels indicating more aggressive tumors. Another embodiment is the evaluation of the integrity of 24P4C12 nucleotide and amino acid sequences in a biological sample, in order to identify perturbations in the structure of these molecules such as insertions, deletions, substitutions and the like. The presence of one or more perturbations indicates more aggressive tumors.
Another embodiment of the invention is directed to methods for observing the progression of a malignancy in an individual over time. In one embodiment, methods for observing the progression of a malignancy in an individual over time comprise determining the level of 24P4C12 mRNA or 24P4C12 protein expressed by cells in a sample of the tumor, comparing the level so determined to the level of 24P4C12 mRNA or 24P4C12 protein expressed in an equivalent tissue sample taken from the same individual at a different time, wherein the degree of 24P4C12 mRNA or 24P4C12 protein expression in the tumor sample over time provides information on the progression of the cancer. In a specific embodiment, the progression of a cancer is evaluated by determining 24P4C12 expression in the tumor cells over time, where increased expression over time indicates a progression of the cancer. Also, one can evaluate the integrity 24P4C12 nucleotide and amino acid sequences in a biological sample in order to identify perturbations in the structure of these molecules such as insertions, deletions, substitutions and the like, where the presence of one or more perturbations indicates a progression of the cancer.
The above diagnostic approaches can be combined with any one of a wide variety of prognostic and diagnostic protocols known in the art. For example, another embodiment of the invention is directed to methods for observing a coincidence between the expression of 24P4C12 gene and 24P4C12 gene products (or perturbations in 24P4C12 gene and 24P4C12 gene products) and a factor that is associated with malignancy, as a means for diagnosing and prognosticating the status of a tissue sample. A wide variety of factors associated with malignancy can be utilized, such as the expression of genes associated with malignancy as well as gross cytological observations (see, e.g., Bocking et al., 1984, Anal. Quant. Cytol. 6(2):74-88; Epstein, 1995, Hum. Pathol. 26(2):223-9; Thorson et al., 1998, Mod. Pathol. 11(6):543-51; Baisden et al., 1999, Am. J. Surg. Pathol. 23(8):918-24). Methods for observing a coincidence between the expression of 24P4C12 gene and 24P4C12 gene products (or perturbations in 24P4C12 gene and 24P4C12 gene products) and another factor that is associated with malignancy are useful, for example, because the presence of a set of specific factors that coincide with disease provides information crucial for diagnosing and prognosticating the status of a tissue sample.
Methods for detecting and quantifying the expression of 24P4C12 mRNA or protein are described herein, and standard nucleic acid and protein detection and quantification technologies are well known in the art. Standard methods for the detection and quantification of 24P4C12 mRNA include in situ hybridization using labeled 24P4C12 riboprobes, Northern blot and related techniques using 24P4C12 polynucleotide probes, RT-PCR analysis using primers specific for 24P4C12, and other amplification type detection methods, such as, for example, branched DNA, SISBA, TMA and the like. In a specific embodiment, semi-quantitative RT-PCR is used to detect and quantify 24P4C12 mRNA expression. Any number of primers capable of amplifying 24P4C12 can be used for this purpose, including but not limited to the various primer sets specifically described herein. In a specific embodiment, polyclonal or monoclonal antibodies specifically reactive with the wild-type 24P4C12 protein can be used in an immunohistochemical assay of biopsied tissue.
VIII.) Identification of Molecules that Interact with 24P4C12
The 24P4C12 protein and nucleic acid sequences disclosed herein allow a skilled artisan to identify proteins, small molecules and other agents that interact with 24P4C12, as well as pathways activated by 24P4C12 via any one of a variety of art accepted protocols. For example, one can utilize one of the so-called interaction trap systems (also referred to as the “two-hybrid assay”). In such systems, molecules interact and reconstitute a transcription factor which directs expression of a reporter gene, whereupon the expression of the reporter gene is assayed. Other systems identify protein-protein interactions in vivo through reconstitution of a eukaryotic transcriptional activator, see, e.g., U.S. Pat. No. 5,955,280 issued 21 Sep. 1999, U.S. Pat. No. 5,925,523 issued 20 Jul. 1999, 5,846,722 issued 8 Dec. 1998 and U.S. Pat. No. 6,004,746 issued 21 Dec. 1999. Algorithms are also available in the art for genome-based predictions of protein function (see, e.g., Marcotte, et al., Nature 402: 4 Nov. 1999, 83-86).
Alternatively one can screen peptide libraries to identify molecules that interact with 24P4C12 protein sequences. In such methods, peptides that bind to 24P4C12 are identified by screening libraries that encode a random or controlled collection of amino acids. Peptides encoded by the libraries are expressed as fusion proteins of bacteriophage coat proteins, the bacteriophage particles are then screened against the 24P4C12 protein(s).
Accordingly, peptides having a wide variety of uses, such as therapeutic, prognostic or diagnostic reagents, are thus identified without any prior information on the structure of the expected ligand or receptor molecule. Typical peptide libraries and screening methods that can be used to identify molecules that interact with 24P4C12 protein sequences are disclosed for example in U.S. Pat. No. 5,723,286 issued 3 Mar. 1998 and U.S. Pat. No. 5,733,731 issued 31 Mar. 1998.
Alternatively, cell lines that express 24P4C12 are used to identify protein-protein interactions mediated by 24P4C12. Such interactions can be examined using immunoprecipitation techniques (see, e.g., Hamilton B. J., et al. Biochem. Biophys. Res. Commun. 1999, 261:646-51). 24P4C12 protein can be immunoprecipitated from 24P4C12-expressing cell lines using anti-24P4C12 antibodies. Alternatively, antibodies against His-tag can be used in a cell line engineered to express fusions of 24P4C12 and a His-tag (vectors mentioned above). The immunoprecipitated complex can be examined for protein association by procedures such as Western blotting, 35S-methionine labeling of proteins, protein microsequencing, silver staining and two-dimensional gel electrophoresis.
Small molecules and ligands that interact with 24P4C12 can be identified through related embodiments of such screening assays. For example, small molecules can be identified that interfere with protein function, including molecules that interfere with 24P4C12's ability to mediate phosphorylation and de-phosphorylation, interaction with DNA or RNA molecules as an indication of regulation of cell cycles, second messenger signaling or tumorigenesis. Similarly, small molecules that modulate 24P4C12-related ion channel, transporter, protein pump, or cell communication functions are identified and used to treat patients that have a cancer that expresses 24P4C12 (see, e.g., Hille, B., Ionic Channels of Excitable Membranes 2nd Ed., Sinauer Assoc., Sunderland, Mass., 1992). Moreover, ligands that regulate 24P4C12 function can be identified based on their ability to bind 24P4C12 and activate a reporter construct. Typical methods are discussed for example in U.S. Pat. No. 5,928,868 issued 27 Jul. 1999, and include methods for forming hybrid ligands in which at least one ligand is a small molecule. In an illustrative embodiment, cells engineered to express a fusion protein of 24P4C12 and a DNA-binding protein are used to co-express a fusion protein of a hybrid ligand/small molecule and a cDNA library transcriptional activator protein. The cells further contain a reporter gene, the expression of which is conditioned on the proximity of the first and second fusion proteins to each other, an event that occurs only if the hybrid ligand binds to target sites on both hybrid proteins. Those cells that express the reporter gene are selected and the unknown small molecule or the unknown ligand is identified. This method provides a means of identifying modulators, which activate or inhibit 24P4C12.
An embodiment of this invention comprises a method of screening for a molecule that interacts with a 24P4C12 amino acid sequence shown in
IX.) Therapeutic Methods and Compositions
The identification of 24P4C12 as a protein that is normally expressed in a restricted set of tissues, but which is also expressed in cancers such as those listed in Table I, opens a number of therapeutic approaches to the treatment of such cancers.
Of note, targeted antitumor therapies have been useful even when the targeted protein is expressed on normal tissues, even vital normal organ tissues. A vital organ is one that is necessary to sustain life, such as the heart or colon. A non-vital organ is one that can be removed whereupon the individual is still able to survive. Examples of non-vital organs are ovary, breast, and prostate.
For example, Herceptin® is an FDA approved pharmaceutical that consists of an antibody which is immunoreactive with the protein variously known as HER2, HER2/neu, and erb-b-2. It is marketed by Genentech and has been a commercially successful antitumor agent. Herceptin® sales reached almost $400 million in 2002. Herceptin® is a treatment for HER2 positive metastatic breast cancer. However, the expression of HER2 is not limited to such tumors. The same protein is expressed in a number of normal tissues. In particular, it is known that HER2/neu is present in normal kidney and heart, thus these tissues are present in all human recipients of Herceptin. The presence of HER2/neu in normal kidney is also confirmed by Latif, Z., et al., B.J.U. International (2002) 89:5-9. As shown in this article (which evaluated whether renal cell carcinoma should be a preferred indication for anti-HER2 antibodies such as Herceptin) both protein and mRNA are produced in benign renal tissues. Notably, HER2/neu protein was strongly overexpressed in benign renal tissue.
Despite the fact that HER2/neu is expressed in such vital tissues as heart and kidney, Herceptin is a very useful, FDA approved, and commercially successful drug. The effect of Herceptin on cardiac tissue, i.e., “cardiotoxicity,” has merely been a side effect to treatment. When patients were treated with Herceptin alone, significant cardiotoxicity occurred in a very low percentage of patients. To minimize cariotoxicity there is a more stringent entry requirement for the treatment with HER2/neu. Factors such as predisposition to heart condition are evaluated before treatment can occur.
Of particular note, although kidney tissue is indicated to exhibit normal expression, possibly even higher expression than cardiac tissue, kidney has no appreciable Herceptin side effect whatsoever. Moreover, of the diverse array of normal tissues in which HER2 is expressed, there is very little occurrence of any side effect. Only cardiac tissue has manifested any appreciable side effect at all. A tissue such as kidney, where HER2/neu expression is especially notable, has not been the basis for any side effect.
Furthermore, favorable therapeutic effects have been found for antitumor therapies that target epidermal growth factor receptor (EGFR); Erbitux (InClone). EGFR is also expressed in numerous normal tissues. There have been very limited side effects in normal tissues following use of anti-EGFR therapeutics. A general side effect that occurs with the EGFR treatment is a severe skin rash observed in 100% of the patients undergoing treatment.
Thus, expression of a target protein in normal tissue, even vital normal tissue, does not defeat the utility of a targeting agent for the protein as a therapeutic for certain tumors in which the protein is also overexpressed. For example, expression in vital organs is not in and of itself detrimental. In addition, organs regarded as dispensible, such as the prostate and ovary, can be removed without affecting mortality. Finally, some vital organs are not affected by normal organ expression because of an immunoprivilege. Immunoprivileged organs are organs that are protected from blood by a blood-organ barrier and thus are not accessible to immunotherapy. Examples of immunoprivileged organs are the brain and testis.
Accordingly, therapeutic approaches that inhibit the activity of a 24P4C12 protein are useful for patients suffering from a cancer that expresses 24P4C12. These therapeutic approaches generally fall into three classes. The first class modulates 24P4C12 function as it relates to tumor cell growth leading to inhibition or retardation of tumor cell growth or inducing its killing. The second class comprises various methods for inhibiting the binding or association of a 24P4C12 protein with its binding partner or with other proteins. The third class comprises a variety of methods for inhibiting the transcription of a 24P4C12 gene or translation of 24P4C12 mRNA.
IX.A.) Anti-Cancer Vaccines
The invention provides cancer vaccines comprising a 24P4C12-related protein or 24P4C12-related nucleic acid. In view of the expression of 24P4C12, cancer vaccines prevent and/or treat 24P4C12-expressing cancers with minimal or no effects on non-target tissues. The use of a tumor antigen in a vaccine that generates cell-mediated humoral immune responses as anti-cancer therapy is well known in the art and has been employed in prostate cancer using human PSMA and rodent PAP immunogens (Hodge et al., 1995, Int. J. Cancer 63:231-237; Fong et al., 1997, J. Immunol. 159:3113-3117).
Such methods can be readily practiced by employing a 24P4C12-related protein, or a 24P4C12-encoding nucleic acid molecule and recombinant vectors capable of expressing and presenting the 24P4C12 immunogen (which typically comprises a number of T-cell epitopes or antibody). Skilled artisans understand that a wide variety of vaccine systems for delivery of immunoreactive epitopes are known in the art (see, e.g., Heryln et al., Ann Med 1999 February 31(1):66-78; Maruyama et al., Cancer Immunol Immunother 2000 June 49(3):123-32) Briefly, such methods of generating an immune response (e.g. cell-mediated and/or humoral) in a mammal, comprise the steps of: exposing the mammal's immune system to an immunoreactive epitope (e.g. an epitope present in a 24P4C12 protein shown in
The entire 24P4C12 protein, immunogenic regions or epitopes thereof can be combined and delivered by various means. Such vaccine compositions can include, for example, lipopeptides (e.g., Vitiello, A. et al., J. Clin. Invest. 95:341, 1995), peptide compositions encapsulated in poly(DL-lactide-co-glycolide) (“PLG”) microspheres (see, e.g., Eldridge, et al., Molec. Immunol. 28:287-294, 1991: Alonso et al., Vaccine 12:299-306, 1994; Jones et al., Vaccine 13:675-681, 1995), peptide compositions contained in immune stimulating complexes (ISCOMS) (see, e.g., Takahashi et al., Nature 344:873-875, 1990; Hu et al., Clin Exp Immunol. 113:235-243, 1998), multiple antigen peptide systems (MAPs) (see e.g., Tam, J. P., Proc. Natl. Acad. Sci. U.S.A. 85:5409-5413, 1988; Tam, J. P., J. Immunol. Methods 196:17-32, 1996), peptides formulated as multivalent peptides; peptides for use in ballistic delivery systems, typically crystallized peptides, viral delivery vectors (Perkus, M. E. et al., In: Concepts in vaccine development, Kaufmann, S. H. E., ed., p. 379, 1996; Chakrabarti, S. et al., Nature 320:535, 1986; Hu, S. L. et al., Nature 320:537, 1986; Kieny, M.-P. et al., AIDS Bio/Technology 4:790, 1986; Top, F. H. et al., J. Infect. Dis. 124:148, 1971; Chanda, P. K. et al., Virology 175:535, 1990), particles of viral or synthetic origin (e.g., Kofler, N. et al., J. Immunol. Methods. 192:25, 1996; Eldridge, J. H. et al., Sem. Hematol. 30:16, 1993; Falo, L. D., Jr. et al., Nature Med. 7:649, 1995), adjuvants (Warren, H. S., Vogel, F. R., and Chedid, L. A. Annu. Rev. Immunol. 4:369, 1986; Gupta, R. K. et al., Vaccine 11:293, 1993), liposomes (Reddy, R. et al., J. Immunol. 148:1585, 1992; Rock, K. L., Immunol. Today 17:131, 1996), or, naked or particle absorbed cDNA (Ulmer, J. B. et al., Science 259:1745, 1993; Robinson, H. L., Hunt, L. A., and Webster, R. G., Vaccine 11:957, 1993; Shiver, J. W. et al., In: Concepts in vaccine development, Kaufmann, S. H. E., ed., p. 423, 1996; Cease, K. B., and Berzofsky, J. A., Annu. Rev. Immunol. 12:923, 1994 and Eldridge, J. H. et al., Sem. Hematol. 30:16, 1993). Toxin-targeted delivery technologies, also known as receptor mediated targeting, such as those of Avant Immunotherapeutics, Inc. (Needham, Mass.) may also be used.
In patients with 24P4C12-associated cancer, the vaccine and antibody compositions of the invention can also be used in conjunction with other treatments used for cancer, e.g., surgery, chemotherapy, drug therapies, radiation therapies, etc. including use in combination with immune adjuvants such as IL-2, IL-12, GM-CSF, and the like.
CTL epitopes can be determined using specific algorithms to identify peptides within 24P4C12 protein that bind corresponding HLA alleles (e.g., Brown University, BIMAS, and SYFPEITHI. In a preferred embodiment, a 24P4C12 immunogen contains one or more amino acid sequences identified using techniques well known in the art, such as the sequences shown in Tables previously disclosed or a peptide of 8, 9, 10 or 11 amino acids specified by an HLA Class I motif/supermotif (e.g., Table IV (A), Table IV (D), or Table IV (E)) and/or a peptide of at least 9 amino acids that comprises an HLA Class II motif/supermotif (e.g., Table IV (B) or Table IV (C)). As is appreciated in the art, the HLA Class I binding groove is essentially closed ended so that peptides of only a particular size range can fit into the groove and be bound, generally HLA Class I epitopes are 8, 9, 10, or 11 amino acids long. In contrast, the HLA Class II binding groove is essentially open ended; therefore a peptide of about 9 or more amino acids can be bound by an HLA Class II molecule. Due to the binding groove differences between HLA Class I and II, HLA Class I motifs are length specific, i.e., position two of a Class I motif is the second amino acid in an amino to carboxyl direction of the peptide. The amino acid positions in a Class II motif are relative only to each other, not the overall peptide, i.e., additional amino acids can be attached to the amino and/or carboxyl termini of a motif-bearing sequence. HLA Class II epitopes are often 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 amino acids long, or longer than 25 amino acids.
A wide variety of methods for generating an immune response in a mammal are known in the art (for example as the first step in the generation of hybridomas). Methods of generating an immune response in a mammal comprise exposing the mammal's immune system to an immunogenic epitope on a protein (e.g. a 24P4C12 protein) so that an immune response is generated. A typical embodiment consists of a method for generating an immune response to 24P4C12 in a host, by contacting the host with a sufficient amount of at least one 24P4C12 B cell or cytotoxic T-cell epitope or analog thereof; and at least one periodic interval thereafter re-contacting the host with the 24P4C12 B cell or cytotoxic T-cell epitope or analog thereof. A specific embodiment consists of a method of generating an immune response against a 24P4C12-related protein or a man-made multiepitopic peptide comprising: administering 24P4C12 immunogen (e.g. a 24P4C12 protein or a peptide fragment thereof, a 24P4C12 fusion protein or analog etc.) in a vaccine preparation to a human or another mammal. Typically, such vaccine preparations further contain a suitable adjuvant (see, e.g., U.S. Pat. No. 6,146,635) or a universal helper epitope such as a PADRE™ peptide (Epimmune Inc., San Diego, Calif.; see, e.g., Alexander et al., J. Immunol. 2000 164(3); 164(3): 1625-1633; Alexander et al., Immunity 1994 1(9): 751-761 and Alexander et al., Immunol. Res. 1998 18(2): 79-92). An alternative method comprises generating an immune response in an individual against a 24P4C12 immunogen by: administering in vivo to muscle or skin of the individual's body a DNA molecule that comprises a DNA sequence that encodes a 24P4C12 immunogen, the DNA sequence operatively linked to regulatory sequences which control the expression of the DNA sequence; wherein the DNA molecule is taken up by cells, the DNA sequence is expressed in the cells and an immune response is generated against the immunogen (see, e.g., U.S. Pat. No. 5,962,428). Optionally a genetic vaccine facilitator such as anionic lipids; saponins; lectins; estrogenic compounds; hydroxylated lower alkyls; dimethyl sulfoxide; and urea is also administered. In addition, an antiidiotypic antibody can be administered that mimics 24P4C12, in order to generate a response to the target antigen.
Nucleic Acid Vaccines:
Vaccine compositions of the invention include nucleic acid-mediated modalities. DNA or RNA that encode protein(s) of the invention can be administered to a patient. Genetic immunization methods can be employed to generate prophylactic or therapeutic humoral and cellular immune responses directed against cancer cells expressing 24P4C12. Constructs comprising DNA encoding a 24P4C12-related protein/immunogen and appropriate regulatory sequences can be injected directly into muscle or skin of an individual, such that the cells of the muscle or skin take-up the construct and express the encoded 24P4C12 protein/immunogen. Alternatively, a vaccine comprises a 24P4C12-related protein. Expression of the 24P4C12-related protein immunogen results in the generation of prophylactic or therapeutic humoral and cellular immunity against cells that bear a 24P4C12 protein. Various prophylactic and therapeutic genetic immunization techniques known in the art can be used. Nucleic acid-based delivery is described, for instance, in Wolff et. al., Science 247:1465 (1990) as well as U.S. Pat. Nos. 5,580,859; 5,589,466; 5,804,566; 5,739,118; 5,736,524; 5,679,647; WO 98/04720. Examples of DNA-based delivery technologies include “naked DNA”, facilitated (bupivicaine, polymers, peptide-mediated) delivery, cationic lipid complexes, and particle-mediated (“gene gun”) or pressure-mediated delivery (see, e.g., U.S. Pat. No. 5,922,687).
For therapeutic or prophylactic immunization purposes, proteins of the invention can be expressed via viral or bacterial vectors. Various viral gene delivery systems that can be used in the practice of the invention include, but are not limited to, vaccinia, fowlpox, canarypox, adenovirus, influenza, poliovirus, adeno-associated virus, lentivirus, and sindbis virus (see, e.g., Restifo, 1996, Curr. Opin. Immunol. 8:658-663; Tsang et al. J. Natl. Cancer Inst. 87:982-990 (1995)). Non-viral delivery systems can also be employed by introducing naked DNA encoding a 24P4C12-related protein into the patient (e.g., intramuscularly or intradermally) to induce an anti-tumor response.
Vaccinia virus is used, for example, as a vector to express nucleotide sequences that encode the peptides of the invention. Upon introduction into a host, the recombinant vaccinia virus expresses the protein immunogenic peptide, and thereby elicits a host immune response. Vaccinia vectors and methods useful in immunization protocols are described in, e.g., U.S. Pat. No. 4,722,848. Another vector is BCG (Bacille Calmette Guerin). BCG vectors are described in Stover et al., Nature 351:456-460 (1991). A wide variety of other vectors useful for therapeutic administration or immunization of the peptides of the invention, e.g. adeno and adeno-associated virus vectors, retroviral vectors, Salmonella typhi vectors, detoxified anthrax toxin vectors, and the like, will be apparent to those skilled in the art from the description herein.
Thus, gene delivery systems are used to deliver a 24P4C12-related nucleic acid molecule. In one embodiment, the full-length human 24P4C12 cDNA is employed. In another embodiment, 24P4C12 nucleic acid molecules encoding specific cytotoxic T lymphocyte (CTL) and/or antibody epitopes are employed.
Ex Vivo Vaccines
Various ex vivo strategies can also be employed to generate an immune response. One approach involves the use of antigen presenting cells (APCs) such as dendritic cells (DC) to present 24P4C12 antigen to a patient's immune system. Dendritic cells express MHC class I and II molecules, B7 co-stimulator, and IL-12, and are thus highly specialized antigen presenting cells. In prostate cancer, autologous dendritic cells pulsed with peptides of the prostate-specific membrane antigen (PSMA) are being used in a Phase I clinical trial to stimulate prostate cancer patients' immune systems (Tjoa et al., 1996, Prostate 28:65-69; Murphy et al., 1996, Prostate 29:371-380). Thus, dendritic cells can be used to present 24P4C12 peptides to T cells in the context of MHC class I or II molecules. In one embodiment, autologous dendritic cells are pulsed with 24P4C12 peptides capable of binding to MHC class I and/or class II molecules. In another embodiment, dendritic cells are pulsed with the complete 24P4C12 protein. Yet another embodiment involves engineering the overexpression of a 24P4C12 gene in dendritic cells using various implementing vectors known in the art, such as adenovirus (Arthur et al., 1997, Cancer Gene Ther. 4:17-25), retrovirus (Henderson et al., 1996, Cancer Res. 56:3763-3770), lentivirus, adeno-associated virus, DNA transfection (Ribas et al., 1997, Cancer Res. 57:2865-2869), or tumor-derived RNA transfection (Ashley et al., 1997, J. Exp. Med. 186:1177-1182). Cells that express 24P4C12 can also be engineered to express immune modulators, such as GM-CSF, and used as immunizing agents.
IX.B.) 24P4C12 as a Target for Antibody-Based Therapy
24P4C12 is an attractive target for antibody-based therapeutic strategies. A number of antibody strategies are known in the art for targeting both extracellular and intracellular molecules (see, e.g., complement and ADCC mediated killing as well as the use of intrabodies). Because 24P4C12 is expressed by cancer cells of various lineages relative to corresponding normal cells, systemic administration of 24P4C12-immunoreactive compositions are prepared that exhibit excellent sensitivity without toxic, non-specific and/or non-target effects caused by binding of the immunoreactive composition to non-target organs and tissues. Antibodies specifically reactive with domains of 24P4C12 are useful to treat 24P4C12-expressing cancers systemically, either as conjugates with a toxin or therapeutic agent, or as naked antibodies capable of inhibiting cell proliferation or function.
24P4C12 antibodies can be introduced into a patient such that the antibody binds to 24P4C12 and modulates a function, such as an interaction with a binding partner, and consequently mediates destruction of the tumor cells and/or inhibits the growth of the tumor cells. Mechanisms by which such antibodies exert a therapeutic effect can include complement-mediated cytolysis, antibody-dependent cellular cytotoxicity, modulation of the physiological function of 24P4C12, inhibition of ligand binding or signal transduction pathways, modulation of tumor cell differentiation, alteration of tumor angiogenesis factor profiles, and/or apoptosis.
Those skilled in the art understand that antibodies can be used to specifically target and bind immunogenic molecules such as an immunogenic region of a 24P4C12 sequence shown in
A wide variety of compositions and methods for using antibody-cytotoxic agent conjugates to kill cells are known in the art. In the context of cancers, typical methods entail administering to an animal having a tumor a biologically effective amount of a conjugate comprising a selected cytotoxic and/or therapeutic agent linked to a targeting agent (e.g. an anti-24P4C12 antibody) that binds to a marker (e.g. 24P4C12) expressed, accessible to binding or localized on the cell surfaces. A typical embodiment is a method of delivering a cytotoxic and/or therapeutic agent to a cell expressing 24P4C12, comprising conjugating the cytotoxic agent to an antibody that immunospecifically binds to a 24P4C12 epitope, and, exposing the cell to the antibody-agent conjugate. Another illustrative embodiment is a method of treating an individual suspected of suffering from metastasized cancer, comprising a step of administering parenterally to said individual a pharmaceutical composition comprising a therapeutically effective amount of an antibody conjugated to a cytotoxic and/or therapeutic agent.
Cancer immunotherapy using anti-24P4C12 antibodies can be done in accordance with various approaches that have been successfully employed in the treatment of other types of cancer, including but not limited to colon cancer (Arlen et al., 1998, Crit. Rev. Immunol. 18:133-138), multiple myeloma (Ozaki et al., 1997, Blood 90:3179-3186, Tsunenari et al., 1997, Blood 90:2437-2444), gastric cancer (Kasprzyk et al., 1992, Cancer Res. 52:2771-2776), B-cell lymphoma (Funakoshi et al., 1996, J. Immunother. Emphasis Tumor Immunol. 19:93-101), leukemia (Zhong et al., 1996, Leuk. Res. 20:581-589), colorectal cancer (Moun et al., 1994, Cancer Res. 54:6160-6166; Velders et al., 1995, Cancer Res. 55:4398-4403), and breast cancer (Shepard et al., 1991, J. Clin. Immunol. 11:117-127). Some therapeutic approaches involve conjugation of naked antibody to a toxin or radioisotope, such as the conjugation of Y91 or I131 to anti-CD20 antibodies (e.g., Zevalin™, IDEC Pharmaceuticals Corp. or Bexxar™, Coulter Pharmaceuticals) respectively, while others involve co-administration of antibodies and other therapeutic agents, such as Herceptin™ (trastuzu MAb) with paclitaxel (Genentech, Inc.). The antibodies can be conjugated to a therapeutic agent. To treat prostate cancer, for example, 24P4C12 antibodies can be administered in conjunction with radiation, chemotherapy or hormone ablation. Also, antibodies can be conjugated to a toxin such as calicheamicin (e.g., Mylotarg™, Wyeth-Ayerst, Madison, N.J., a recombinant humanized IgG4 kappa antibody conjugated to antitumor antibiotic calicheamicin) or a maytansinoid (e.g., taxane-based Tumor-Activated Prodrug, TAP, platform, ImmunoGen, Cambridge, Mass., also see e.g., U.S. Pat. No. 5,416,064) or Auristatin E (Nat. Biotechnol. 2003 July; 21(7):778-84. (Seattle Genetics)).
Although 24P4C12 antibody therapy is useful for all stages of cancer, antibody therapy can be particularly appropriate in advanced or metastatic cancers. Treatment with the antibody therapy of the invention is indicated for patients who have received one or more rounds of chemotherapy. Alternatively, antibody therapy of the invention is combined with a chemotherapeutic or radiation regimen for patients who have not received chemotherapeutic treatment. Additionally, antibody therapy can enable the use of reduced dosages of concomitant chemotherapy, particularly for patients who do not tolerate the toxicity of the chemotherapeutic agent very well. Fan et al. (Cancer Res. 53:4637-4642, 1993), Prewett et al. (International J. of Onco. 9:217-224, 1996), and Hancock et al. (Cancer Res. 51:4575-4580, 1991) describe the use of various antibodies together with chemotherapeutic agents.
Although 24P4C12 antibody therapy is useful for all stages of cancer, antibody therapy can be particularly appropriate in advanced or metastatic cancers. Treatment with the antibody therapy of the invention is indicated for patients who have received one or more rounds of chemotherapy. Alternatively, antibody therapy of the invention is combined with a chemotherapeutic or radiation regimen for patients who have not received chemotherapeutic treatment. Additionally, antibody therapy can enable the use of reduced dosages of concomitant chemotherapy, particularly for patients who do not tolerate the toxicity of the chemotherapeutic agent very well.
Cancer patients can be evaluated for the presence and level of 24P4C12 expression, preferably using immunohistochemical assessments of tumor tissue, quantitative 24P4C12 imaging, or other techniques that reliably indicate the presence and degree of 24P4C12 expression. Immunohistochemical analysis of tumor biopsies or surgical specimens is preferred for this purpose. Methods for immunohistochemical analysis of tumor tissues are well known in the art.
Anti-24P4C12 monoclonal antibodies that treat prostate and other cancers include those that initiate a potent immune response against the tumor or those that are directly cytotoxic. In this regard, anti-24P4C12 monoclonal antibodies (MAbs) can elicit tumor cell lysis by either complement-mediated or antibody-dependent cell cytotoxicity (ADCC) mechanisms, both of which require an intact Fc portion of the immunoglobulin molecule for interaction with effector cell Fc receptor sites on complement proteins. In addition, anti-24P4C12 MAbs that exert a direct biological effect on tumor growth are useful to treat cancers that express 24P4C12. Mechanisms by which directly cytotoxic MAbs act include: inhibition of cell growth, modulation of cellular differentiation, modulation of tumor angiogenesis factor profiles, and the induction of apoptosis. The mechanism(s) by which a particular anti-24P4C12 MAb exerts an anti-tumor effect is evaluated using any number of in vitro assays that evaluate cell death such as ADCC, ADMMC, complement-mediated cell lysis, and so forth, as is generally known in the art.
In some patients, the use of murine or other non-human monoclonal antibodies, or human/mouse chimeric MAbs can induce moderate to strong immune responses against the non-human antibody. This can result in clearance of the antibody from circulation and reduced efficacy. In the most severe cases, such an immune response can lead to the extensive formation of immune complexes which, potentially, can cause renal failure. Accordingly, preferred monoclonal antibodies used in the therapeutic methods of the invention are those that are either fully human or humanized and that bind specifically to the target 24P4C12 antigen with high affinity but exhibit low or no antigenicity in the patient.
Therapeutic methods of the invention contemplate the administration of single anti-24P4C12 MAbs as well as combinations, or cocktails, of different MAbs (i.e. 24P4C12 MAbs or Mabs that bind another protein). Such MAb cocktails can have certain advantages inasmuch as they contain MAbs that target different epitopes, exploit different effector mechanisms or combine directly cytotoxic MAbs with MAbs that rely on immune effector functionality. Such MAbs in combination can exhibit synergistic therapeutic effects. In addition, 24P4C12 MAbs can be administered concomitantly with other therapeutic modalities, including but not limited to various chemotherapeutic and biologic agents, androgen-blockers, immune modulators (e.g., IL-2, GM-CSF), surgery or radiation. The 24P4C12 MAbs are administered in their “naked” or unconjugated form, or can have a therapeutic agent(s) conjugated to them.
24P4C12 Mab formulations are administered via any route capable of delivering the antibodies to a tumor cell. Routes of administration include, but are not limited to, intravenous, intraperitoneal, intramuscular, intratumor, intradermal, and the like. Treatment generally involves repeated administration of the 24P4C12 MAb preparation, via an acceptable route of administration such as intravenous injection (IV), typically at a dose in the range, including but not limited to, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, or 25 mg/kg body weight. In general, doses in the range of 10-1000 mg MAb per week are effective and well tolerated.
Based on clinical experience with the Herceptin® (Trastuzumab) in the treatment of metastatic breast cancer, an initial loading dose of approximately 4 mg/kg patient body weight IV, followed by weekly doses of about 2 mg/kg IV of the MAb preparation represents an acceptable dosing regimen. Preferably, the initial loading dose is administered as a 90-minute or longer infusion. The periodic maintenance dose is administered as a 30 minute or longer infusion, provided the initial dose was well tolerated. As appreciated by those of skill in the art, various factors can influence the ideal dose regimen in a particular case. Such factors include, for example, the binding affinity and half life of the MAbs used, the degree of 24P4C12 expression in the patient, the extent of circulating shed 24P4C12 antigen, the desired steady-state antibody concentration level, frequency of treatment, and the influence of chemotherapeutic or other agents used in combination with the treatment method of the invention, as well as the health status of a particular patient.
Optionally, patients should be evaluated for the levels of 24P4C12 in a given sample (e.g. the levels of circulating 24P4C12 antigen and/or 24P4C12 expressing cells) in order to assist in the determination of the most effective dosing regimen, etc. Such evaluations are also used for monitoring purposes throughout therapy, and are useful to gauge therapeutic success in combination with the evaluation of other parameters (for example, urine cytology and/or ImmunoCyt levels in bladder cancer therapy, or by analogy, serum PSA levels in prostate cancer therapy).
Anti-idiotypic anti-24P4C12 antibodies can also be used in anti-cancer therapy as a vaccine for inducing an immune response to cells expressing a 24P4C12-related protein. In particular, the generation of anti-idiotypic antibodies is well known in the art; this methodology can readily be adapted to generate anti-idiotypic anti-24P4C12 antibodies that mimic an epitope on a 24P4C12-related protein (see, for example, Wagner et al., 1997, Hybridoma 16: 33-40; Foon et al., 1995, J. Clin. Invest. 96:334-342; Herlyn et al., 1996, Cancer Immunol. Immunother. 43:65-76). Such an anti-idiotypic antibody can be used in cancer vaccine strategies.
An object of the present invention is to provide 24P4C12 Mabs, which inhibit or retard the growth of tumor cells expressing 24P4C12. A further object of this invention is to provide methods to inhibit angiogenesis and other biological functions and thereby reduce tumor growth in mammals, preferably humans, using such 24P4C12 MAbs, and in particular using such 24P4C12 MAbs combined with other drugs or immunologically active treatments, including but not limited to: Avastin® (bevacizumab), Sutent® (sunitinib malate), Nexavar® (Sorafinib tosylate), Taxotere® (docetaxel), Interleukin-2 (a.k.a. Proleukin®, IL-2, or Aldesleukin), Interferon Alpha (Interferon-Alpha-2a, or Interferon-Alpha-2b), Paraplatin® (carboplatin) or Gemzar® (gemcitibine) and others in the art known to treat different cancers.
In one embodiment, there is synergy when tumors, including human tumors, are treated with 24P4C12 antibodies in conjunction with chemotherapeutic agents or radiation or combinations thereof. In other words, the inhibition of tumor growth by a 24P4C12 antibody is enhanced more than expected when combined with chemotherapeutic agents or radiation or combinations thereof. Synergy may be shown, for example, by greater inhibition of tumor growth with combined treatment than would be expected from a treatment of only 24P4C12 antibodies or the additive effect of treatment with a 24P4C12 antibody and a chemotherapeutic agent or radiation. Preferably, synergy is demonstrated by remission of the cancer where remission is not expected from treatment either from a naked 24P4C12 antibody or with treatment using an additive combination of a 24P4C12 antibody and a chemotherapeutic agent or radiation.
The method for inhibiting growth of tumor cells using a 24P4C12 antibody and a combination of chemotherapy or radiation or both comprises administering the 24P4C12 antibody before, during, or after commencing chemotherapy or radiation therapy, as well as any combination thereof (i.e. before and during, before and after, during and after, or before, during, and after commencing the chemotherapy and/or radiation therapy). For example, the 24P4C12 antibody is typically administered between 1 and 60 days, preferably between 3 and 40 days, more preferably between 5 and 12 days before commencing radiation therapy and/or chemotherapy. However, depending on the treatment protocol and the specific patient needs, the method is performed in a manner that will provide the most efficacious treatment and ultimately prolong the life of the patient.
The administration of chemotherapeutic agents can be accomplished in a variety of ways including systemically by the parenteral and enteral routes. In one embodiment, the 24P4C12 antibody and the chemotherapeutic agent are administered as separate molecules. In another embodiment, the 24P4C12 antibody is attached, for example, by conjugation, to a chemotherapeutic agent. (See the Example entitled “Human Clinical Trials for the Treatment and Diagnosis of Human Carcinomas through use of 24P4C12 Mabs”). Particular examples of chemotherapeutic agents or chemotherapy include cisplatin, dacarbazine (DTIC), dactinomycin, mechlorethamine (nitrogen mustard), streptozocin, cyclophosphamide, carmustine (BCNU), lomustine (CCNU), doxorubicin (adriamycin), daunorubicin, procarbazine, mitomycin, cytarabine, etoposide, methotrexate, 5-fluorouracil, vinblastine, vincristine, bleomycin, paclitaxel (taxol), docetaxel (taxotere), aldesleukin, asparaginase, busulfan, carboplatin, cladribine, dacarbazine, floxuridine, fludarabine, hydroxyurea, ifosfamide, interferon alpha, leuprolide, megestrol, melphalan, mercaptopurine, plicamycin, mitotane, pegaspargase, pentostatin, pipobroman, plicamycin, streptozocin, tamoxifen, teniposide, testolactone, thioguanine, thiotepa, uracil mustard, vinorelbine, chlorambucil, taxol and combinations thereof.
The source of radiation, used in combination with a 24P4C12 Mab, can be either external or internal to the patient being treated. When the source is external to the patient, the therapy is known as external beam radiation therapy (EBRT). When the source of radiation is internal to the patient, the treatment is called brachytherapy (BT).
The above described therapeutic regimens may be further combined with additional cancer treating agents and/or regimes, for example additional chemotherapy, cancer vaccines, signal transduction inhibitors, agents useful in treating abnormal cell growth or cancer, antibodies (e.g. Anti-CTLA-4 antibodies as described in WO/2005/092380 (Pfizer)) or other ligands that inhibit tumor growth by binding to IGF-1R, and cytokines.
When the mammal is subjected to additional chemotherapy, chemotherapeutic agents described above may be used. Additionally, growth factor inhibitors, biological response modifiers, anti-hormonal therapy, selective estrogen receptor modulators (SERMs), angiogenesis inhibitors, and anti-androgens may be used. For example, anti-hormones, for example anti-estrogens such as Nolvadex (tamoxifen) or, anti-androgens such as Casodex (4′-cyano-3-(4-fluorophenylsulphonyl)-2-hydroxy-2-methyl-3-′-(trifluoromethyl)propionanilide) may be used.
In certain embodiments of the invention, the above described methods are combined with a cancer vaccine. Useful vaccines may be, without limitation, those comprised of cancer-associated antigens (e.g. BAGE, carcinoembryonic antigen (CEA), EBV, GAGE, gp100 (including gp100:209-217 and gp100:280-288, among others), HBV, HER-2/neu, HPV, HCV, MAGE, mammaglobin, MART-1/Melan-A, Mucin-1, NY-ESO-1, proteinase-3, PSA, RAGE, TRP-1, TRP-2, Tyrosinase (e.g., Tyrosinase: 368-376), WT-1), GM-CSF DNA and cell-based vaccines, dendritic cell vaccines, recombinant viral (e.g. vaccinia virus) vaccines, and heat shock protein (HSP) vaccines. Useful vaccines also include tumor vaccines, such as those formed of melanoma cells, and can be autologous or allogeneic. The vaccines may be, e.g., peptide, DNA or cell-based. These various agents can be combined such that a combination comprising, inter alia, gp100 peptides, Tyrosinase and MART-1 can be administered with the antibody.
Vaccines may be administered prior to, or subsequent to, stem cell transplantation, and when chemotherapy is part of the regimen, a vaccine may be administered prior to chemotherapy. In certain embodiments, the antibody of the invention may also be administered prior to chemotherapy. Vaccine may also be administered after stem cell transplantation and in certain embodiments concomitantly with the antibody.
The above described treatments may also be used with signal transduction inhibitors, such as agents that can inhibit EGFR (epidermal growth factor receptor) responses, such as EGFR antibodies, EGF antibodies, and molecules that are EGFR inhibitors; VEGF (vascular endothelial growth factor) inhibitors, such as VEGF receptors and molecules that can inhibit VEGF; and erbB2 receptor inhibitors, such as organic molecules or antibodies that bind to the erbB2 receptor.
EGFR inhibitors are described in, for example in WO 95/19970 (published Jul. 27, 1995), WO 98/14451 (published Apr. 9, 1998), WO 98/02434 (published Jan. 22, 1998), and U.S. Pat. No. 5,747,498 (issued May 5, 1998), and such substances can be used in the present invention as described herein. EGFR-inhibiting agents include, but are not limited to, the monoclonal antibodies ERBITUX (ImClone Systems Incorporated of New York, N.Y.), and VECTIBIX (AMGEN Fremont Inc. of Fremont, Calif.), the compounds ZD-1839 (AstraZeneca), BIBX-1382 (Boehringer Ingelheim), MDX-447 (Medarex Inc. of Annandale, N.J.), and OLX-103 (Merck & Co. of Whitehouse Station, N.J.), VRCTC-310 (Ventech Research) and EGF fusion toxin (Seragen Inc. of Hopkinton, Mass.). These and other EGFR-inhibiting agents can be used in the present invention.
VEGF inhibitors, for example SU-5416 and SU-6668 (Sugen Inc. of South San Francisco, Calif.), can also be employed in combination with the antibody. VEGF inhibitors are described for example in WO 99/24440 (published May 20, 1999), PCT International Application PCT/IB99/00797 (filed May 3, 1999), in WO 95/21613 (published Aug. 17, 1995), WO 99/61422 (published Dec. 2, 1999), U.S. Pat. No. 5,834,504 (issued Nov. 10, 1998), WO 98/50356 (published Nov. 12, 1998), U.S. Pat. No. 5,883,113 (issued Mar. 16, 1999), U.S. Pat. No. 5,886,020 (issued Mar. 23, 1999), U.S. Pat. No. 5,792,783 (issued Aug. 11, 1998), WO 99/10349 (published Mar. 4, 1999), WO 97/32856 (published Sep. 12, 1997), WO 97/22596 (published Jun. 26, 1997), WO 98/54093 (published Dec. 3, 1998), WO 98/02438 (published Jan. 22, 1998), WO 99/16755 (published Apr. 8, 1999), and WO 98/02437 (published Jan. 22, 1998). Other examples of some specific VEGF inhibitors useful in the present invention are IM862 (Cytran Inc. of Kirkland, Wash.); IMC-IC11 Imclone antibody and angiozyme, a synthetic ribozyme from Ribozyme (Boulder, Colo.) and Chiron (Emeryville, Calif.).
ErbB2 receptor inhibitors, such as GW-282974 (Glaxo Wellcome), and the monoclonal antibodies AR-209 (Aronex Pharmaceuticals Inc. of The Woodlands, Tex.) and 2B-1 (Chiron), can furthermore be combined with the antibody, for example those indicated in WO 98/02434 (published Jan. 22, 1998), WO 99/35146 (published Jul. 15, 1999), WO 99/35132 (published Jul. 15, 1999), WO 98/02437 (published Jan. 22, 1998), WO 97/13760 (published Apr. 17, 1997), WO 95/19970 (published Jul. 27, 1995), U.S. Pat. No. 5,587,458 (issued Dec. 24, 1996), and U.S. Pat. No. 5,877,305 (issued Mar. 2, 1999). ErbB2 receptor inhibitors useful in the present invention are also described in EP1029853 (published Aug. 23, 2000) and in WO 00/44728, (published Aug. 3, 2000). The erbB2 receptor inhibitor compounds and substance described in the aforementioned PCT applications, U.S. patents, and U.S. provisional applications, as well as other compounds and substances that inhibit the erbB2 receptor, can be used with the antibody in accordance with the present invention.
The present treatment regimens may also be combined with antibodies or other ligands that inhibit tumor growth by binding to IGF-1R (insulin-like growth factor 1 receptor). Specific anti-IGF-1R antibodies that can be used in the present invention include those described in PCT application PCT/US01/51113, filed Dec. 20, 2001 and published as WO02/053596.
The treatment regimens described herein may be combined with anti-angiogenesis agents, such as MMP-2 (matrix-metalloproteinase 2) inhibitors, MMP-9 (matrix-metalloproteinase 9) inhibitors, and COX-II (cyclooxygenase II) inhibitors, can be used in conjunction with the antibody in the method of the invention. Examples of useful COX-II inhibitors include CELEBREX (celecoxib), valdecoxib, and rofecoxib.
IX.C.) 24P4C12 as a Target for Cellular Immune Responses
Vaccines and methods of preparing vaccines that contain an immunogenically effective amount of one or more HLA-binding peptides as described herein are further embodiments of the invention. Furthermore, vaccines in accordance with the invention encompass compositions of one or more of the claimed peptides. A peptide can be present in a vaccine individually. Alternatively, the peptide can exist as a homopolymer comprising multiple copies of the same peptide, or as a heteropolymer of various peptides. Polymers have the advantage of increased immunological reaction and, where different peptide epitopes are used to make up the polymer, the additional ability to induce antibodies and/or CTLs that react with different antigenic determinants of the pathogenic organism or tumor-related peptide targeted for an immune response. The composition can be a naturally occurring region of an antigen or can be prepared, e.g., recombinantly or by chemical synthesis.
Carriers that can be used with vaccines of the invention are well known in the art, and include, e.g., thyroglobulin, albumins such as human serum albumin, tetanus toxoid, polyamino acids such as poly L-lysine, poly L-glutamic acid, influenza, hepatitis B virus core protein, and the like. The vaccines can contain a physiologically tolerable (i.e., acceptable) diluent such as water, or saline, preferably phosphate buffered saline. The vaccines also typically include an adjuvant. Adjuvants such as incomplete Freund's adjuvant, aluminum phosphate, aluminum hydroxide, or alum are examples of materials well known in the art. Additionally, as disclosed herein, CTL responses can be primed by conjugating peptides of the invention to lipids, such as tripalmitoyl-5-glycerylcysteinlyseryl-serine (P3CSS). Moreover, an adjuvant such as synthetic cytosine-phosphorothiolated-guanine-containing (CpG) oligonucleotides has been found to increase CTL responses 10- to 100-fold (see, e.g. Davila and Celis, J. Immunol. 165:539-547 (2000)).
Upon immunization with a peptide composition in accordance with the invention, via injection, aerosol, oral, transdermal, transmucosal, intrapleural, intrathecal, or other suitable routes, the immune system of the host responds to the vaccine by producing large amounts of CTLs and/or helper T-lymphocytes (HTLs) specific for the desired antigen. Consequently, the host becomes at least partially immune to later development of cells that express or overexpress 24P4C12 antigen, or derives at least some therapeutic benefit when the antigen was tumor-associated.
In some embodiments, it may be desirable to combine the class I peptide components with components that induce or facilitate neutralizing antibody and or helper T cell responses directed to the target antigen. A preferred embodiment of such a composition comprises class I and class II epitopes in accordance with the invention. An alternative embodiment of such a composition comprises a class I and/or class II epitope in accordance with the invention, along with a cross reactive HTL epitope such as PADRE™ (Epimmune, San Diego, Calif.) molecule (described e.g., in U.S. Pat. No. 5,736,142).
A vaccine of the invention can also include antigen-presenting cells (APC), such as dendritic cells (DC), as a vehicle to present peptides of the invention. Vaccine compositions can be created in vitro, following dendritic cell mobilization and harvesting, whereby loading of dendritic cells occurs in vitro. For example, dendritic cells are transfected, e.g., with a minigene in accordance with the invention, or are pulsed with peptides. The dendritic cell can then be administered to a patient to elicit immune responses in vivo. Vaccine compositions, either DNA- or peptide-based, can also be administered in vivo in combination with dendritic cell mobilization whereby loading of dendritic cells occurs in vivo.
Preferably, the following principles are utilized when selecting an array of epitopes for inclusion in a polyepitopic composition for use in a vaccine, or for selecting discrete epitopes to be included in a vaccine and/or to be encoded by nucleic acids such as a minigene. It is preferred that each of the following principles be balanced in order to make the selection. The multiple epitopes to be incorporated in a given vaccine composition may be, but need not be, contiguous in sequence in the native antigen from which the epitopes are derived.
1.) Epitopes are selected which, upon administration, mimic immune responses that have been observed to be correlated with tumor clearance. For HLA Class I this includes 3-4 epitopes that come from at least one tumor associated antigen (TAA). For HLA Class II a similar rationale is employed; again 3-4 epitopes are selected from at least one TAA (see, e.g., Rosenberg et al., Science 278:1447-1450). Epitopes from one TAA may be used in combination with epitopes from one or more additional TAAs to produce a vaccine that targets tumors with varying expression patterns of frequently-expressed TAAs.
2.) Epitopes are selected that have the requisite binding affinity established to be correlated with immunogenicity: for HLA Class I an IC50 of 500 nM or less, often 200 nM or less; and for Class II an IC50 of 1000 nM or less.
3.) Sufficient supermotif bearing-peptides, or a sufficient array of allele-specific motif-bearing peptides, are selected to give broad population coverage. For example, it is preferable to have at least 80% population coverage. A Monte Carlo analysis, a statistical evaluation known in the art, can be employed to assess the breadth, or redundancy of, population coverage.
4.) When selecting epitopes from cancer-related antigens it is often useful to select analogs because the patient may have developed tolerance to the native epitope.
5.) Of particular relevance are epitopes referred to as “nested epitopes.” Nested epitopes occur where at least two epitopes overlap in a given peptide sequence. A nested peptide sequence can comprise B cell, HLA class I and/or HLA class II epitopes. When providing nested epitopes, a general objective is to provide the greatest number of epitopes per sequence. Thus, an aspect is to avoid providing a peptide that is any longer than the amino terminus of the amino terminal epitope and the carboxyl terminus of the carboxyl terminal epitope in the peptide. When providing a multi-epitopic sequence, such as a sequence comprising nested epitopes, it is generally important to screen the sequence in order to insure that it does not have pathological or other deleterious biological properties.
6.) If a polyepitopic protein is created, or when creating a minigene, an objective is to generate the smallest peptide that encompasses the epitopes of interest. This principle is similar, if not the same as that employed when selecting a peptide comprising nested epitopes. However, with an artificial polyepitopic peptide, the size minimization objective is balanced against the need to integrate any spacer sequences between epitopes in the polyepitopic protein. Spacer amino acid residues can, for example, be introduced to avoid junctional epitopes (an epitope recognized by the immune system, not present in the target antigen, and only created by the man-made juxtaposition of epitopes), or to facilitate cleavage between epitopes and thereby enhance epitope presentation. Junctional epitopes are generally to be avoided because the recipient may generate an immune response to that non-native epitope. Of particular concern is a junctional epitope that is a “dominant epitope.” A dominant epitope may lead to such a zealous response that immune responses to other epitopes are diminished or suppressed.
7.) Where the sequences of multiple variants of the same target protein are present, potential peptide epitopes can also be selected on the basis of their conservancy. For example, a criterion for conservancy may define that the entire sequence of an HLA class I binding peptide or the entire 9-mer core of a class II binding peptide be conserved in a designated percentage of the sequences evaluated for a specific protein antigen.
IX.C.1. Minigene Vaccines
A number of different approaches are available which allow simultaneous delivery of multiple epitopes. Nucleic acids encoding the peptides of the invention are a particularly useful embodiment of the invention. Epitopes for inclusion in a minigene are preferably selected according to the guidelines set forth in the previous section. A preferred means of administering nucleic acids encoding the peptides of the invention uses minigene constructs encoding a peptide comprising one or multiple epitopes of the invention.
The use of multi-epitope minigenes is described below and in, Ishioka et al., J. Immunol. 162:3915-3925, 1999; An, L. and Whitton, J. L., J. Virol. 71:2292, 1997; Thomson, S. A. et al., J. Immunol. 157:822, 1996; Whitton, J. L. et al., J. Virol. 67:348, 1993; Hanke, R. et al., Vaccine 16:426, 1998. For example, a multi-epitope DNA plasmid encoding supermotif- and/or motif-bearing epitopes derived 24P4C12, the PADRE™ universal helper T cell epitope or multiple HTL epitopes from 24P4C12, and an endoplasmic reticulum-translocating signal sequence can be engineered. A vaccine may also comprise epitopes that are derived from other TAAs.
The immunogenicity of a multi-epitopic minigene can be confirmed in transgenic mice to evaluate the magnitude of CTL induction responses against the epitopes tested. Further, the immunogenicity of DNA-encoded epitopes in vivo can be correlated with the in vitro responses of specific CTL lines against target cells transfected with the DNA plasmid. Thus, these experiments can show that the minigene serves to both: 1.) generate a CTL response and 2.) that the induced CTLs recognized cells expressing the encoded epitopes.
For example, to create a DNA sequence encoding the selected epitopes (minigene) for expression in human cells, the amino acid sequences of the epitopes may be reverse translated. A human codon usage table can be used to guide the codon choice for each amino acid. These epitope-encoding DNA sequences may be directly adjoined, so that when translated, a continuous polypeptide sequence is created. To optimize expression and/or immunogenicity, additional elements can be incorporated into the minigene design. Examples of amino acid sequences that can be reverse translated and included in the minigene sequence include: HLA class I epitopes, HLA class II epitopes, antibody epitopes, a ubiquitination signal sequence, and/or an endoplasmic reticulum targeting signal. In addition, HLA presentation of CTL and HTL epitopes may be improved by including synthetic (e.g. poly-alanine) or naturally-occurring flanking sequences adjacent to the CTL or HTL epitopes; these larger peptides comprising the epitope(s) are within the scope of the invention.
The minigene sequence may be converted to DNA by assembling oligonucleotides that encode the plus and minus strands of the minigene. Overlapping oligonucleotides (30-100 bases long) may be synthesized, phosphorylated, purified and annealed under appropriate conditions using well known techniques. The ends of the oligonucleotides can be joined, for example, using T4 DNA ligase. This synthetic minigene, encoding the epitope polypeptide, can then be cloned into a desired expression vector.
Standard regulatory sequences well known to those of skill in the art are preferably included in the vector to ensure expression in the target cells. Several vector elements are desirable: a promoter with a down-stream cloning site for minigene insertion; a polyadenylation signal for efficient transcription termination; an E. coli origin of replication; and an E. coli selectable marker (e.g., ampicillin or kanamycin resistance). Numerous promoters can be used for this purpose, e.g., the human cytomegalovirus (hCMV) promoter. See, e.g., U.S. Pat. Nos. 5,580,859 and 5,589,466 for other suitable promoter sequences.
Additional vector modifications may be desired to optimize minigene expression and immunogenicity. In some cases, introns are required for efficient gene expression, and one or more synthetic or naturally-occurring introns could be incorporated into the transcribed region of the minigene. The inclusion of mRNA stabilization sequences and sequences for replication in mammalian cells may also be considered for increasing minigene expression.
Once an expression vector is selected, the minigene is cloned into the polylinker region downstream of the promoter. This plasmid is transformed into an appropriate E. coli strain, and DNA is prepared using standard techniques. The orientation and DNA sequence of the minigene, as well as all other elements included in the vector, are confirmed using restriction mapping and DNA sequence analysis. Bacterial cells harboring the correct plasmid can be stored as a master cell bank and a working cell bank.
In addition, immunostimulatory sequences (ISSs or CpGs) appear to play a role in the immunogenicity of DNA vaccines. These sequences may be included in the vector, outside the minigene coding sequence, if desired to enhance immunogenicity.
In some embodiments, a bi-cistronic expression vector which allows production of both the minigene-encoded epitopes and a second protein (included to enhance or decrease immunogenicity) can be used. Examples of proteins or polypeptides that could beneficially enhance the immune response if co-expressed include cytokines (e.g., IL-2, IL-12, GM-CSF), cytokine-inducing molecules (e.g., LeIF), costimulatory molecules, or for HTL responses, pan-DR binding proteins (PADRE™, Epimmune, San Diego, Calif.). Helper (HTL) epitopes can be joined to intracellular targeting signals and expressed separately from expressed CTL epitopes; this allows direction of the HTL epitopes to a cell compartment different than that of the CTL epitopes. If required, this could facilitate more efficient entry of HTL epitopes into the HLA class II pathway, thereby improving HTL induction. In contrast to HTL or CTL induction, specifically decreasing the immune response by co-expression of immunosuppressive molecules (e.g. TGF-β) may be beneficial in certain diseases.
Therapeutic quantities of plasmid DNA can be produced for example, by fermentation in E. coli, followed by purification. Aliquots from the working cell bank are used to inoculate growth medium, and grown to saturation in shaker flasks or a bioreactor according to well-known techniques. Plasmid DNA can be purified using standard bioseparation technologies such as solid phase anion-exchange resins supplied by QIAGEN, Inc. (Valencia, Calif.). If required, supercoiled DNA can be isolated from the open circular and linear forms using gel electrophoresis or other methods.
Purified plasmid DNA can be prepared for injection using a variety of formulations. The simplest of these is reconstitution of lyophilized DNA in sterile phosphate-buffer saline (PBS). This approach, known as “naked DNA,” is currently being used for intramuscular (IM) administration in clinical trials. To maximize the immunotherapeutic effects of minigene DNA vaccines, an alternative method for formulating purified plasmid DNA may be desirable. A variety of methods have been described, and new techniques may become available. Cationic lipids, glycolipids, and fusogenic liposomes can also be used in the formulation (see, e.g., as described by WO 93/24640; Mannino & Gould-Fogerite, BioTechniques 6(7): 682 (1988); U.S. Pat. No. 5,279,833; WO 91/06309; and Felgner, et al., Proc. Nat'l Acad. Sci. USA 84:7413 (1987). In addition, peptides and compounds referred to collectively as protective, interactive, non-condensing compounds (PINC) could also be complexed to purified plasmid DNA to influence variables such as stability, intramuscular dispersion, or trafficking to specific organs or cell types.
Target cell sensitization can be used as a functional assay for expression and HLA class I presentation of minigene-encoded CTL epitopes. For example, the plasmid DNA is introduced into a mammalian cell line that is suitable as a target for standard CTL chromium release assays. The transfection method used will be dependent on the final formulation. Electroporation can be used for “naked” DNA, whereas cationic lipids allow direct in vitro transfection. A plasmid expressing green fluorescent protein (GFP) can be co-transfected to allow enrichment of transfected cells using fluorescence activated cell sorting (FACS). These cells are then chromium-51 (51Cr) labeled and used as target cells for epitope-specific CTL lines; cytolysis, detected by 51Cr release, indicates both production of, and HLA presentation of, minigene-encoded CTL epitopes. Expression of HTL epitopes may be evaluated in an analogous manner using assays to assess HTL activity.
In vivo immunogenicity is a second approach for functional testing of minigene DNA formulations. Transgenic mice expressing appropriate human HLA proteins are immunized with the DNA product. The dose and route of administration are formulation dependent (e.g., IM for DNA in PBS, intraperitoneal (i.p.) for lipid-complexed DNA). Twenty-one days after immunization, splenocytes are harvested and restimulated for one week in the presence of peptides encoding each epitope being tested. Thereafter, for CTL effector cells, assays are conducted for cytolysis of peptide-loaded, 51Cr-labeled target cells using standard techniques. Lysis of target cells that were sensitized by HLA loaded with peptide epitopes, corresponding to minigene-encoded epitopes, demonstrates DNA vaccine function for in vivo induction of CTLs. Immunogenicity of HTL epitopes is confirmed in transgenic mice in an analogous manner.
Alternatively, the nucleic acids can be administered using ballistic delivery as described, for instance, in U.S. Pat. No. 5,204,253. Using this technique, particles comprised solely of DNA are administered. In a further alternative embodiment, DNA can be adhered to particles, such as gold particles.
Minigenes can also be delivered using other bacterial or viral delivery systems well known in the art, e.g., an expression construct encoding epitopes of the invention can be incorporated into a viral vector such as vaccinia.
IX.C.2. Combinations of CTL Peptides with Helper Peptides
Vaccine compositions comprising CTL peptides of the invention can be modified, e.g., analoged, to provide desired attributes, such as improved serum half life, broadened population coverage or enhanced immunogenicity.
For instance, the ability of a peptide to induce CTL activity can be enhanced by linking the peptide to a sequence which contains at least one epitope that is capable of inducing a T helper cell response. Although a CTL peptide can be directly linked to a T helper peptide, often CTL epitope/HTL epitope conjugates are linked by a spacer molecule. The spacer is typically comprised of relatively small, neutral molecules, such as amino acids or amino acid mimetics, which are substantially uncharged under physiological conditions. The spacers are typically selected from, e.g., Ala, Gly, or other neutral spacers of nonpolar amino acids or neutral polar amino acids. It will be understood that the optionally present spacer need not be comprised of the same residues and thus may be a hetero- or homo-oligomer. When present, the spacer will usually be at least one or two residues, more usually three to six residues and sometimes 10 or more residues. The CTL peptide epitope can be linked to the T helper peptide epitope either directly or via a spacer either at the amino or carboxy terminus of the CTL peptide. The amino terminus of either the immunogenic peptide or the T helper peptide may be acylated.
HTL peptide epitopes can also be modified to alter their biological properties. For example, they can be modified to include D-amino acids to increase their resistance to proteases and thus extend their serum half life, or they can be conjugated to other molecules such as lipids, proteins, carbohydrates, and the like to increase their biological activity. For example, a T helper peptide can be conjugated to one or more palmitic acid chains at either the amino or carboxyl termini.
IX.C.3. Combinations of CTL Peptides with T Cell Priming Agents
In some embodiments it may be desirable to include in the pharmaceutical compositions of the invention at least one component which primes B lymphocytes or T lymphocytes. Lipids have been identified as agents capable of priming CTL in vivo. For example, palmitic acid residues can be attached to the ε- and α-amino groups of a lysine residue and then linked, e.g., via one or more linking residues such as Gly, Gly-Gly-, Ser, Ser-Ser, or the like, to an immunogenic peptide. The lipidated peptide can then be administered either directly in a micelle or particle, incorporated into a liposome, or emulsified in an adjuvant, e.g., incomplete Freund's adjuvant. In a preferred embodiment, a particularly effective immunogenic composition comprises palmitic acid attached to ε- and α-amino groups of Lys, which is attached via linkage, e.g., Ser-Ser, to the amino terminus of the immunogenic peptide.
As another example of lipid priming of CTL responses, E. coli lipoproteins, such as tripalmitoyl-5-glycerylcysteinlyseryl-serine (P3CSS) can be used to prime virus specific CTL when covalently attached to an appropriate peptide (see, e.g., Deres, et al., Nature 342:561, 1989). Peptides of the invention can be coupled to P3CSS, for example, and the lipopeptide administered to an individual to prime specifically an immune response to the target antigen. Moreover, because the induction of neutralizing antibodies can also be primed with P3CSS-conjugated epitopes, two such compositions can be combined to more effectively elicit both humoral and cell-mediated responses.
IX.C.4. Vaccine Compositions Comprising DC Pulsed with CTL and/or HTL Peptides
An embodiment of a vaccine composition in accordance with the invention comprises ex vivo administration of a cocktail of epitope-bearing peptides to PBMC, or isolated DC therefrom, from the patient's blood. A pharmaceutical to facilitate harvesting of DC can be used, such as Progenipoietin™ (Pharmacia-Monsanto, St. Louis, Mo.) or GM-CSF/IL-4. After pulsing the DC with peptides and prior to reinfusion into patients, the DC are washed to remove unbound peptides. In this embodiment, a vaccine comprises peptide-pulsed DCs which present the pulsed peptide epitopes complexed with HLA molecules on their surfaces.
The DC can be pulsed ex vivo with a cocktail of peptides, some of which stimulate CTL responses to 24P4C12. Optionally, a helper T cell (HTL) peptide, such as a natural or artificial loosely restricted HLA Class II peptide, can be included to facilitate the CTL response. Thus, a vaccine in accordance with the invention is used to treat a cancer which expresses or overexpresses 24P4C12.
IX.D.) Adoptive Immunotherapy
Antigenic 24P4C12-related peptides are used to elicit a CTL and/or HTL response ex vivo, as well. The resulting CTL or HTL cells, can be used to treat tumors in patients that do not respond to other conventional forms of therapy, or will not respond to a therapeutic vaccine peptide or nucleic acid in accordance with the invention. Ex vivo CTL or HTL responses to a particular antigen are induced by incubating in tissue culture the patient's, or genetically compatible, CTL or HTL precursor cells together with a source of antigen-presenting cells (APC), such as dendritic cells, and the appropriate immunogenic peptide. After an appropriate incubation time (typically about 7-28 days), in which the precursor cells are activated and expanded into effector cells, the cells are infused back into the patient, where they will destroy (CTL) or facilitate destruction (HTL) of their specific target cell (e.g., a tumor cell). Transfected dendritic cells may also be used as antigen presenting cells.
IX.E.) Administration of Vaccines for Therapeutic or Prophylactic Purposes
Pharmaceutical and vaccine compositions of the invention are typically used to treat and/or prevent a cancer that expresses or overexpresses 24P4C12. In therapeutic applications, peptide and/or nucleic acid compositions are administered to a patient in an amount sufficient to elicit an effective B cell, CTL and/or HTL response to the antigen and to cure or at least partially arrest or slow symptoms and/or complications. An amount adequate to accomplish this is defined as “therapeutically effective dose.” Amounts effective for this use will depend on, e.g., the particular composition administered, the manner of administration, the stage and severity of the disease being treated, the weight and general state of health of the patient, and the judgment of the prescribing physician.
For pharmaceutical compositions, the immunogenic peptides of the invention, or DNA encoding them, are generally administered to an individual already bearing a tumor that expresses 24P4C12. The peptides or DNA encoding them can be administered individually or as fusions of one or more peptide sequences. Patients can be treated with the immunogenic peptides separately or in conjunction with other treatments, such as surgery, as appropriate.
For therapeutic use, administration should generally begin at the first diagnosis of 24P4C12-associated cancer. This is followed by boosting doses until at least symptoms are substantially abated and for a period thereafter. The embodiment of the vaccine composition (i.e., including, but not limited to embodiments such as peptide cocktails, polyepitopic polypeptides, minigenes, or TAA-specific CTLs or pulsed dendritic cells) delivered to the patient may vary according to the stage of the disease or the patient's health status. For example, in a patient with a tumor that expresses 24P4C12, a vaccine comprising 24P4C12-specific CTL may be more efficacious in killing tumor cells in patient with advanced disease than alternative embodiments.
It is generally important to provide an amount of the peptide epitope delivered by a mode of administration sufficient to stimulate effectively a cytotoxic T cell response; compositions which stimulate helper T cell responses can also be given in accordance with this embodiment of the invention.
The dosage for an initial therapeutic immunization generally occurs in a unit dosage range where the lower value is about 1, 5, 50, 500, or 1,000 μg and the higher value is about 10,000; 20,000; 30,000; or 50,000 μg. Dosage values for a human typically range from about 500 μg to about 50,000 μg per 70 kilogram patient. Boosting dosages of between about 1.0 μg to about 50,000 μg of peptide pursuant to a boosting regimen over weeks to months may be administered depending upon the patient's response and condition as determined by measuring the specific activity of CTL and HTL obtained from the patient's blood. Administration should continue until at least clinical symptoms or laboratory tests indicate that the neoplasia, has been eliminated or reduced and for a period thereafter. The dosages, routes of administration, and dose schedules are adjusted in accordance with methodologies known in the art.
In certain embodiments, the peptides and compositions of the present invention are employed in serious disease states, that is, life-threatening or potentially life threatening situations. In such cases, as a result of the minimal amounts of extraneous substances and the relative nontoxic nature of the peptides in preferred compositions of the invention, it is possible and may be felt desirable by the treating physician to administer substantial excesses of these peptide compositions relative to these stated dosage amounts.
The vaccine compositions of the invention can also be used purely as prophylactic agents. Generally the dosage for an initial prophylactic immunization generally occurs in a unit dosage range where the lower value is about 1, 5, 50, 500, or 1000 μg and the higher value is about 10,000; 20,000; 30,000; or 50,000 μg. Dosage values for a human typically range from about 500 μg to about 50,000 μg per 70 kilogram patient. This is followed by boosting dosages of between about 1.0 μg to about 50,000 μg of peptide administered at defined intervals from about four weeks to six months after the initial administration of vaccine. The immunogenicity of the vaccine can be assessed by measuring the specific activity of CTL and HTL obtained from a sample of the patient's blood.
The pharmaceutical compositions for therapeutic treatment are intended for parenteral, topical, oral, nasal, intrathecal, or local (e.g. as a cream or topical ointment) administration. Preferably, the pharmaceutical compositions are administered parentally, e.g., intravenously, subcutaneously, intradermally, or intramuscularly. Thus, the invention provides compositions for parenteral administration which comprise a solution of the immunogenic peptides dissolved or suspended in an acceptable carrier, preferably an aqueous carrier.
A variety of aqueous carriers may be used, e.g., water, buffered water, 0.8% saline, 0.3% glycine, hyaluronic acid and the like. These compositions may be sterilized by conventional, well-known sterilization techniques, or may be sterile filtered. The resulting aqueous solutions may be packaged for use as is, or lyophilized, the lyophilized preparation being combined with a sterile solution prior to administration.
The compositions may contain pharmaceutically acceptable auxiliary substances as required to approximate physiological conditions, such as pH-adjusting and buffering agents, tonicity adjusting agents, wetting agents, preservatives, and the like, for example, sodium acetate, sodium lactate, sodium chloride, potassium chloride, calcium chloride, sorbitan monolaurate, triethanolamine oleate, etc.
The concentration of peptides of the invention in the pharmaceutical formulations can vary widely, i.e., from less than about 0.1%, usually at or at least about 2% to as much as 20% to 50% or more by weight, and will be selected primarily by fluid volumes, viscosities, etc., in accordance with the particular mode of administration selected.
A human unit dose form of a composition is typically included in a pharmaceutical composition that comprises a human unit dose of an acceptable carrier, in one embodiment an aqueous carrier, and is administered in a volume/quantity that is known by those of skill in the art to be used for administration of such compositions to humans (see, e.g., Remington's Pharmaceutical Sciences, 17th Edition, A. Gennaro, Editor, Mack Publishing Co., Easton, Pa., 1985). For example a peptide dose for initial immunization can be from about 1 to about 50,000 μg, generally 100-5,000 μg, for a 70 kg patient. For example, for nucleic acids an initial immunization may be performed using an expression vector in the form of naked nucleic acid administered IM (or SC or ID) in the amounts of 0.5-5 mg at multiple sites. The nucleic acid (0.1 to 1000 μg) can also be administered using a gene gun. Following an incubation period of 3-4 weeks, a booster dose is then administered. The booster can be recombinant fowlpox virus administered at a dose of 5-107 to 5×109 pfu.
For antibodies, a treatment generally involves repeated administration of the anti-24P4C12 antibody preparation, via an acceptable route of administration such as intravenous injection (IV), typically at a dose in the range of about 0.1 to about 10 mg/kg body weight. In general, doses in the range of 10-500 mg MAb per week are effective and well tolerated. Moreover, an initial loading dose of approximately 4 mg/kg patient body weight IV, followed by weekly doses of about 2 mg/kg IV of the anti-24P4C12 MAb preparation represents an acceptable dosing regimen. As appreciated by those of skill in the art, various factors can influence the ideal dose in a particular case. Such factors include, for example, half life of a composition, the binding affinity of an Ab, the immunogenicity of a substance, the degree of 24P4C12 expression in the patient, the extent of circulating shed 24P4C12 antigen, the desired steady-state concentration level, frequency of treatment, and the influence of chemotherapeutic or other agents used in combination with the treatment method of the invention, as well as the health status of a particular patient. Non-limiting preferred human unit doses are, for example, 500 μg-1 mg, 1 mg-50 mg, 50 mg-100 mg, 100 mg-200 mg, 200 mg-300 mg, 400 mg-500 mg, 500 mg-600 mg, 600 mg-700 mg, 700 mg-800 mg, 800 mg-900 mg, 900 mg-1 g, or 1 mg-700 mg. In certain embodiments, the dose is in a range of 2-5 mg/kg body weight, e.g., with follow on weekly doses of 1-3 mg/kg; 0.5 mg, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 mg/kg body weight followed, e.g., in two, three or four weeks by weekly doses; 0.5-10 mg/kg body weight, e.g., followed in two, three or four weeks by weekly doses; 225, 250, 275, 300, 325, 350, 375, 400 mg m2 of body area weekly; 1-600 mg m2 of body area weekly; 225-400 mg m2 of body area weekly; these does can be followed by weekly doses for 2, 3, 4, 5, 6, 7, 8, 9, 19, 11, 12 or more weeks.
In one embodiment, human unit dose forms of polynucleotides comprise a suitable dosage range or effective amount that provides any therapeutic effect. As appreciated by one of ordinary skill in the art a therapeutic effect depends on a number of factors, including the sequence of the polynucleotide, molecular weight of the polynucleotide and route of administration. Dosages are generally selected by the physician or other health care professional in accordance with a variety of parameters known in the art, such as severity of symptoms, history of the patient and the like. Generally, for a polynucleotide of about 20 bases, a dosage range may be selected from, for example, an independently selected lower limit such as about 0.1, 0.25, 0.5, 1, 2, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400 or 500 mg/kg up to an independently selected upper limit, greater than the lower limit, of about 60, 80, 100, 200, 300, 400, 500, 750, 1000, 1500, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000 or 10,000 mg/kg. For example, a dose may be about any of the following: 0.1 to 100 mg/kg, 0.1 to 50 mg/kg, 0.1 to 25 mg/kg, 0.1 to 10 mg/kg, 1 to 500 mg/kg, 100 to 400 mg/kg, 200 to 300 mg/kg, 1 to 100 mg/kg, 100 to 200 mg/kg, 300 to 400 mg/kg, 400 to 500 mg/kg, 500 to 1000 mg/kg, 500 to 5000 mg/kg, or 500 to 10,000 mg/kg. Generally, parenteral routes of administration may require higher doses of polynucleotide compared to more direct application to the nucleotide to diseased tissue, as do polynucleotides of increasing length.
In one embodiment, human unit dose forms of T-cells comprise a suitable dosage range or effective amount that provides any therapeutic effect. As appreciated by one of ordinary skill in the art, a therapeutic effect depends on a number of factors. Dosages are generally selected by the physician or other health care professional in accordance with a variety of parameters known in the art, such as severity of symptoms, history of the patient and the like. A dose may be about 104 cells to about 106 cells, about 106 cells to about 108 cells, about 108 to about 1011 cells, or about 108 to about 5×1010 cells. A dose may also about 106 cells/m2 to about 1010 cells/m2, or about 106 cells/m to about 108 cells/m2.
Proteins(s) of the invention, and/or nucleic acids encoding the protein(s), can also be administered via liposomes, which may also serve to: 1) target the proteins(s) to a particular tissue, such as lymphoid tissue; 2) to target selectively to diseases cells; or, 3) to increase the half-life of the peptide composition. Liposomes include emulsions, foams, micelles, insoluble monolayers, liquid crystals, phospholipid dispersions, lamellar layers and the like. In these preparations, the peptide to be delivered is incorporated as part of a liposome, alone or in conjunction with a molecule which binds to a receptor prevalent among lymphoid cells (such as monoclonal antibodies which bind to the CD45 antigen) or with other therapeutic or immunogenic compositions. Thus, liposomes either filled or decorated with a desired peptide of the invention can be directed to the site of lymphoid cells, where the liposomes then deliver the peptide compositions. Liposomes for use in accordance with the invention are formed from standard vesicle-forming lipids, which generally include neutral and negatively charged phospholipids and a sterol, such as cholesterol. The selection of lipids is generally guided by consideration of, e.g., liposome size, acid lability and stability of the liposomes in the blood stream. A variety of methods are available for preparing liposomes, as described in, e.g., Szoka, et al., Ann. Rev. Biophys. Bioeng. 9:467 (1980), and U.S. Pat. Nos. 4,235,871, 4,501,728, 4,837,028, and 5,019,369.
For targeting cells of the immune system, a ligand to be incorporated into the liposome can include, e.g., antibodies or fragments thereof specific for cell surface determinants of the desired immune system cells. A liposome suspension containing a peptide may be administered intravenously, locally, topically, etc. in a dose which varies according to, inter alia, the manner of administration, the peptide being delivered, and the stage of the disease being treated.
For solid compositions, conventional nontoxic solid carriers may be used which include, for example, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose, sucrose, magnesium carbonate, and the like. For oral administration, a pharmaceutically acceptable nontoxic composition is formed by incorporating any of the normally employed excipients, such as those carriers previously listed, and generally 10-95% of active ingredient, that is, one or more peptides of the invention, and more preferably at a concentration of 25%-75%.
For aerosol administration, immunogenic peptides are preferably supplied in finely divided form along with a surfactant and propellant. Typical percentages of peptides are about 0.01%-20% by weight, preferably about 1%-10%. The surfactant must, of course, be nontoxic, and preferably soluble in the propellant. Representative of such agents are the esters or partial esters of fatty acids containing from about 6 to 22 carbon atoms, such as caproic, octanoic, lauric, palmitic, stearic, linoleic, linolenic, olesteric and oleic acids with an aliphatic polyhydric alcohol or its cyclic anhydride. Mixed esters, such as mixed or natural glycerides may be employed. The surfactant may constitute about 0.1%-20% by weight of the composition, preferably about 0.25-5%. The balance of the composition is ordinarily propellant. A carrier can also be included, as desired, as with, e.g., lecithin for intranasal delivery.
X.) Diagnostic and Prognostic Embodiments of 24P4C12.
As disclosed herein, 24P4C12 polynucleotides, polypeptides, reactive cytotoxic T cells (CTL), reactive helper T cells (HTL) and anti-polypeptide antibodies are used in well known diagnostic, prognostic and therapeutic assays that examine conditions associated with dysregulated cell growth such as cancer, in particular the cancers listed in Table I (see, e.g., both its specific pattern of tissue expression as well as its overexpression in certain cancers as described for example in the Example entitled “Expression analysis of 24P4C12 in normal tissues, and patient specimens”).
24P4C12 can be analogized to a prostate associated antigen PSA, the archetypal marker that has been used by medical practitioners for years to identify and monitor the presence of prostate cancer (see, e.g., Merrill et al., J. Urol. 163(2): 503-5120 (2000); Polascik et al., J. Urol. August; 162(2):293-306 (1999) and Fortier et al., J. Nat. Cancer Inst. 91(19): 1635-1640 (1999)). A variety of other diagnostic markers are also used in similar contexts including p53 and K-ras (see, e.g., Tulchinsky et al., Int J Mol Med 1999 July 4(1):99-102 and Minimoto et al., Cancer Detect Prev 2000; 24(1):1-12). Therefore, this disclosure of 24P4C12 polynucleotides and polypeptides (as well as 24P4C12 polynucleotide probes and anti-24P4C12 antibodies used to identify the presence of these molecules) and their properties allows skilled artisans to utilize these molecules in methods that are analogous to those used, for example, in a variety of diagnostic assays directed to examining conditions associated with cancer.
Typical embodiments of diagnostic methods which utilize the 24P4C12 polynucleotides, polypeptides, reactive T cells and antibodies are analogous to those methods from well-established diagnostic assays, which employ, (e.g., PSA polynucleotides, polypeptides, reactive T cells and antibodies.) For example, just as PSA polynucleotides are used as probes (for example in Northern analysis, see, e.g., Sharief et al., Biochem. Mol. Biol. Int. 33(3):567-74 (1994)) and primers (for example in PCR analysis, see, e.g., Okegawa et al., J. Urol. 163(4): 1189-1190 (2000)) to observe the presence and/or the level of PSA mRNAs in methods of monitoring PSA overexpression or the metastasis of prostate cancers, the 24P4C12 polynucleotides described herein can be utilized in the same way to detect 24P4C12 overexpression or the metastasis of prostate and other cancers expressing this gene. Alternatively, just as PSA polypeptides are used to generate antibodies specific for PSA which can then be used to observe the presence and/or the level of PSA proteins in methods to monitor PSA protein overexpression (see, e.g., Stephan et al., Urology 55(4):560-3 (2000)) or the metastasis of prostate cells (see, e.g., Alanen et al., Pathol. Res. Pract. 192(3):233-7 (1996)), the 24P4C12 polypeptides described herein can be utilized to generate antibodies for use in detecting 24P4C12 overexpression or the metastasis of prostate cells and cells of other cancers expressing this gene.
Specifically, because metastases involves the movement of cancer cells from an organ of origin (such as the lung or prostate gland etc.) to a different area of the body (such as a lymph node or bone), assays which examine a biological sample for the presence of cells expressing 24P4C12 polynucleotides and/or polypeptides can be used to provide evidence of metastasis. For example, when a biological sample from tissue that does not normally contain 24P4C12-expressing cells is found to contain 24P4C12-expressing cells this finding is indicative of metastasis.
Alternatively 24P4C12 polynucleotides and/or polypeptides can be used to provide evidence of cancer, for example, when cells in a biological sample that do not normally express 24P4C12 or express 24P4C12 at a different level are found to express 24P4C12 or have an increased expression of 24P4C12 (see, e.g., the 24P4C12 expression in the cancers listed in Table I and in patient samples etc. shown in the accompanying Figures). In such assays, artisans may further wish to generate supplementary evidence of metastasis by testing the biological sample for the presence of a second tissue restricted marker (in addition to 24P4C12).
The use of immunohistochemistry to identify the presence of a 24P4C12 polypeptide within a tissue section can indicate an altered state of certain cells within that tissue. It is well understood in the art that the ability of an antibody to localize to a polypeptide that is expressed in cancer cells is a way of diagnosing presence of disease, disease stage, progression and/or tumor aggressiveness. Such an antibody can also detect an altered distribution of the polypeptide within the cancer cells, as compared to corresponding non-malignant tissue.
The 24P4C12 polypeptide and immunogenic compositions are also useful in view of the phenomena of altered subcellular protein localization in disease states. Alteration of cells from normal to diseased state causes changes in cellular morphology and is often associated with changes in subcellular protein localization/distribution. For example, cell membrane proteins that are expressed in a polarized manner in normal cells can be altered in disease, resulting in distribution of the protein in a non-polar manner over the whole cell surface.
The phenomenon of altered subcellular protein localization in a disease state has been demonstrated with MUC1 and Her2 protein expression by use of immunohistochemical means. Normal epithelial cells have a typical apical distribution of MUC1, in addition to some supranuclear localization of the glycoprotein, whereas malignant lesions often demonstrate an apolar staining pattern (Diaz et al, The Breast Journal, 7; 40-45 (2001); Zhang et al, Clinical Cancer Research, 4; 2669-2676 (1998): Cao, et al, The Journal of Histochemistry and Cytochemistry, 45: 1547-1557 (1997)). In addition, normal breast epithelium is either negative for Her2 protein or exhibits only a basolateral distribution whereas malignant cells can express the protein over the whole cell surface (De Potter, et al, International Journal of Cancer, 44; 969-974 (1989): McCormick, et al, 117; 935-943 (2002)). Alternatively, distribution of the protein may be altered from a surface only localization to include diffuse cytoplasmic expression in the diseased state. Such an example can be seen with MUC1 (Diaz, et al, The Breast Journal, 7: 40-45 (2001)).
Alteration in the localization/distribution of a protein in the cell, as detected by immunohistochemical methods, can also provide valuable information concerning the favorability of certain treatment modalities. This last point is illustrated by a situation where a protein may be intracellular in normal tissue, but cell surface in malignant cells; the cell surface location makes the cells favorably amenable to antibody-based diagnostic and treatment regimens. When such an alteration of protein localization occurs for 24P4C12, the 24P4C12 protein and immune responses related thereto are very useful. Use of the 24P4C12 compositions allows those skilled in the art to make important diagnostic and therapeutic decisions.
Immunohistochemical reagents specific to 24P4C12 are also useful to detect metastases of tumors expressing 24P4C12 when the polypeptide appears in tissues where 24P4C12 is not normally produced.
Thus, 24P4C12 polypeptides and antibodies resulting from immune responses thereto are useful in a variety of important contexts such as diagnostic, prognostic, preventative and/or therapeutic purposes known to those skilled in the art.
Additionally, 24P4C12-related proteins or polynucleotides of the invention can be used to treat a pathologic condition characterized by the over-expression of 24P4C12. For example, the amino acid or nucleic acid sequence of
X.A.) Inhibition of 24P4C12 Protein Function
The invention includes various methods and compositions for inhibiting the binding of 24P4C12 to its binding partner or its association with other protein(s) as well as methods for inhibiting 24P4C12 function.
X.B.) Inhibition of 24P4C12 with Intracellular Antibodies
In one approach, a recombinant vector that encodes single chain antibodies that specifically bind to 24P4C12 are introduced into 24P4C12 expressing cells via gene transfer technologies. Accordingly, the encoded single chain anti-24P4C12 antibody is expressed intracellularly, binds to 24P4C12 protein, and thereby inhibits its function. Methods for engineering such intracellular single chain antibodies are well known. Such intracellular antibodies, also known as “intrabodies”, are specifically targeted to a particular compartment within the cell, providing control over where the inhibitory activity of the treatment is focused. This technology has been successfully applied in the art (for review, see Richardson and Marasco, 1995, TIBTECH vol. 13). Intrabodies have been shown to virtually eliminate the expression of otherwise abundant cell surface receptors (see, e.g., Richardson et al., 1995, Proc. Natl. Acad. Sci. USA 92: 3137-3141; Beerli et al., 1994, J. Biol. Chem. 289: 23931-23936; Deshane et al., 1994, Gene Ther. 1: 332-337).
Single chain antibodies comprise the variable domains of the heavy and light chain joined by a flexible linker polypeptide, and are expressed as a single polypeptide. Optionally, single chain antibodies are expressed as a single chain variable region fragment joined to the light chain constant region or the heavy chain constant region (scFv). Well-known intracellular trafficking signals are engineered into recombinant polynucleotide vectors encoding such single chain antibodies in order to target precisely the intrabody to the desired intracellular compartment. For example, intrabodies targeted to the endoplasmic reticulum (ER) are engineered to incorporate a leader peptide and, optionally, a C-terminal ER retention signal, such as the KDEL amino acid motif. Intrabodies intended to exert activity in the nucleus are engineered to include a nuclear localization signal. Lipid moieties are joined to intrabodies in order to tether the intrabody to the cytosolic side of the plasma membrane. Intrabodies can also be targeted to exert function in the cytosol. For example, cytosolic intrabodies are used to sequester factors within the cytosol, thereby preventing them from being transported to their natural cellular destination.
In one embodiment, intrabodies are used to capture 24P4C12 in the nucleus, thereby preventing its activity within the nucleus. Nuclear targeting signals are engineered into such 24P4C12 intrabodies in order to achieve the desired targeting. Such 24P4C12 intrabodies are designed to bind specifically to a particular 24P4C12 domain. In another embodiment, cytosolic intrabodies that specifically bind to a 24P4C12 protein are used to prevent 24P4C12 from gaining access to the nucleus, thereby preventing it from exerting any biological activity within the nucleus (e.g., preventing 24P4C12 from forming transcription complexes with other factors).
X.C.) Inhibition of 24P4C12 with Recombinant Proteins
In another approach, recombinant molecules bind to 24P4C12 and thereby inhibit 24P4C12 function. For example, these recombinant molecules prevent or inhibit 24P4C12 from accessing/binding to its binding partner(s) or associating with other protein(s). Such recombinant molecules can, for example, contain the reactive part(s) of a 24P4C12 specific antibody molecule. In a particular embodiment, the 24P4C12 binding domain of a 24P4C12 binding partner is engineered into a dimeric fusion protein, whereby the fusion protein comprises two 24P4C12 ligand binding domains linked to the Fc portion of a human IgG, such as human IgG1. Such IgG portion can contain, for example, the CH2 and CH3 domains and the hinge region, but not the CH1 domain. Such dimeric fusion proteins are administered in soluble form to patients suffering from a cancer associated with the expression of 24P4C12, whereby the dimeric fusion protein specifically binds to 24P4C12 and blocks 24P4C12 interaction with a binding partner. Such dimeric fusion proteins are further combined into multimeric proteins using known antibody linking technologies.
X.D.) Inhibition of 24P4C12 Transcription or Translation
The present invention also comprises various methods and compositions for inhibiting the transcription of the 24P4C12 gene. Similarly, the invention also provides methods and compositions for inhibiting the translation of 24P4C12 mRNA into protein.
In one approach, a method of inhibiting the transcription of the 24P4C12 gene comprises contacting the 24P4C12 gene with a 24P4C12 antisense polynucleotide. In another approach, a method of inhibiting 24P4C12 mRNA translation comprises contacting a 24P4C12 mRNA with an antisense polynucleotide. In another approach, a 24P4C12 specific ribozyme is used to cleave a 24P4C12 message, thereby inhibiting translation. Such antisense and ribozyme based methods can also be directed to the regulatory regions of the 24P4C12 gene, such as 24P4C12 promoter and/or enhancer elements. Similarly, proteins capable of inhibiting a 24P4C12 gene transcription factor are used to inhibit 24P4C12 mRNA transcription. The various polynucleotides and compositions useful in the aforementioned methods have been described above. The use of antisense and ribozyme molecules to inhibit transcription and translation is well known in the art.
Other factors that inhibit the transcription of 24P4C12 by interfering with 24P4C12 transcriptional activation are also useful to treat cancers expressing 24P4C12. Similarly, factors that interfere with 24P4C12 processing are useful to treat cancers that express 24P4C12. Cancer treatment methods utilizing such factors are also within the scope of the invention.
X.E.) General Considerations for Therapeutic Strategies
Gene transfer and gene therapy technologies can be used to deliver therapeutic polynucleotide molecules to tumor cells synthesizing 24P4C12 (i.e., antisense, ribozyme, polynucleotides encoding intrabodies and other 24P4C12 inhibitory molecules). A number of gene therapy approaches are known in the art. Recombinant vectors encoding 24P4C12 antisense polynucleotides, ribozymes, factors capable of interfering with 24P4C12 transcription, and so forth, can be delivered to target tumor cells using such gene therapy approaches.
The above therapeutic approaches can be combined with any one of a wide variety of surgical, chemotherapy or radiation therapy regimens. The therapeutic approaches of the invention can enable the use of reduced dosages of chemotherapy (or other therapies) and/or less frequent administration, an advantage for all patients and particularly for those that do not tolerate the toxicity of the chemotherapeutic agent well.
The anti-tumor activity of a particular composition (e.g., antisense, ribozyme, intrabody), or a combination of such compositions, can be evaluated using various in vitro and in vivo assay systems. In vitro assays that evaluate therapeutic activity include cell growth assays, soft agar assays and other assays indicative of tumor promoting activity, binding assays capable of determining the extent to which a therapeutic composition will inhibit the binding of 24P4C12 to a binding partner, etc.
In vivo, the effect of a 24P4C12 therapeutic composition can be evaluated in a suitable animal model. For example, xenogenic kidney cancer models can be used, wherein human prostate cancer explants or passaged xenograft tissues are introduced into immune compromised animals, such as nude or SCID mice (Klein et al., 1997, Nature Medicine 3: 402-408). For example, PCT Patent Application WO98/16628 and U.S. Pat. No. 6,107,540 describe various xenograft models of human prostate cancer capable of recapitulating the development of primary tumors, micrometastasis, and the formation of osteoblastic metastases characteristic of late stage disease. Efficacy can be predicted using assays that measure inhibition of tumor formation, tumor regression or metastasis, and the like.
In vivo assays that evaluate the promotion of apoptosis are useful in evaluating therapeutic compositions. In one embodiment, xenografts from tumor bearing mice treated with the therapeutic composition can be examined for the presence of apoptotic foci and compared to untreated control xenograft-bearing mice. The extent to which apoptotic foci are found in the tumors of the treated mice provides an indication of the therapeutic efficacy of the composition.
The therapeutic compositions used in the practice of the foregoing methods can be formulated into pharmaceutical compositions comprising a carrier suitable for the desired delivery method. Suitable carriers include any material that when combined with the therapeutic composition retains the anti-tumor function of the therapeutic composition and is generally non-reactive with the patient's immune system. Examples include, but are not limited to, any of a number of standard pharmaceutical carriers such as sterile phosphate buffered saline solutions, bacteriostatic water, and the like (see, generally, Remington's Pharmaceutical Sciences 16th Edition, A. Osal., Ed., 1980).
Therapeutic formulations can be solubilized and administered via any route capable of delivering the therapeutic composition to the tumor site. Potentially effective routes of administration include, but are not limited to, intravenous, parenteral, intraperitoneal, intramuscular, intratumor, intradermal, intraorgan, orthotopic, and the like. A preferred formulation for intravenous injection comprises the therapeutic composition in a solution of preserved bacteriostatic water, sterile unpreserved water, and/or diluted in polyvinylchloride or polyethylene bags containing 0.9% sterile Sodium Chloride for Injection, USP. Therapeutic protein preparations can be lyophilized and stored as sterile powders, preferably under vacuum, and then reconstituted in bacteriostatic water (containing for example, benzyl alcohol preservative) or in sterile water prior to injection.
Dosages and administration protocols for the treatment of cancers using the foregoing methods will vary with the method and the target cancer, and will generally depend on a number of other factors appreciated in the art.
XI.) Identification, Characterization and Use of Modulators of 24P4C12
Methods to Identify and Use Modulators
In one embodiment, screening is performed to identify modulators that induce or suppress a particular expression profile, suppress or induce specific pathways, preferably generating the associated phenotype thereby. In another embodiment, having identified differentially expressed genes important in a particular state; screens are performed to identify modulators that alter expression of individual genes, either increase or decrease. In another embodiment, screening is performed to identify modulators that alter a biological function of the expression product of a differentially expressed gene. Again, having identified the importance of a gene in a particular state, screens are performed to identify agents that bind and/or modulate the biological activity of the gene product.
In addition, screens are done for genes that are induced in response to a candidate agent. After identifying a modulator (one that suppresses a cancer expression pattern leading to a normal expression pattern, or a modulator of a cancer gene that leads to expression of the gene as in normal tissue) a screen is performed to identify genes that are specifically modulated in response to the agent. Comparing expression profiles between normal tissue and agent-treated cancer tissue reveals genes that are not expressed in normal tissue or cancer tissue, but are expressed in agent treated tissue, and vice versa. These agent-specific sequences are identified and used by methods described herein for cancer genes or proteins. In particular these sequences and the proteins they encode are used in marking or identifying agent-treated cells. In addition, antibodies are raised against the agent-induced proteins and used to target novel therapeutics to the treated cancer tissue sample.
Modulator-Related Identification and Screening Assays:
Gene Expression-Related Assays
Proteins, nucleic acids, and antibodies of the invention are used in screening assays. The cancer-associated proteins, antibodies, nucleic acids, modified proteins and cells containing these sequences are used in screening assays, such as evaluating the effect of drug candidates on a “gene expression profile,” expression profile of polypeptides or alteration of biological function. In one embodiment, the expression profiles are used, preferably in conjunction with high throughput screening techniques to allow monitoring for expression profile genes after treatment with a candidate agent (e.g., Davis, G F, et al, J Biol Screen 7:69 (2002); Zlokarnik, et al., Science 279:84-8 (1998); Heid, Genome Res 6:986-94, 1996).
The cancer proteins, antibodies, nucleic acids, modified proteins and cells containing the native or modified cancer proteins or genes are used in screening assays. That is, the present invention comprises methods for screening for compositions which modulate the cancer phenotype or a physiological function of a cancer protein of the invention. This is done on a gene itself or by evaluating the effect of drug candidates on a “gene expression profile” or biological function. In one embodiment, expression profiles are used, preferably in conjunction with high throughput screening techniques to allow monitoring after treatment with a candidate agent, see Zlokarnik, supra.
A variety of assays are executed and directed to the genes and proteins of the invention. Assays are run on an individual nucleic acid or protein level. That is, having identified a particular gene as up regulated in cancer, test compounds are screened for the ability to modulate gene expression or for binding to the cancer protein of the invention. “Modulation” in this context includes an increase or a decrease in gene expression. The preferred amount of modulation will depend on the original change of the gene expression in normal versus tissue undergoing cancer, with changes of at least 10%, preferably 50%, more preferably 100-300%, and in some embodiments 300-1000% or greater. Thus, if a gene exhibits a 4-fold increase in cancer tissue compared to normal tissue, a decrease of about four-fold is often desired; similarly, a 10-fold decrease in cancer tissue compared to normal tissue a target value of a 10-fold increase in expression by the test compound is often desired. Modulators that exacerbate the type of gene expression seen in cancer are also useful, e.g., as an upregulated target in further analyses.
The amount of gene expression is monitored using nucleic acid probes and the quantification of gene expression levels, or, alternatively, a gene product itself is monitored, e.g., through the use of antibodies to the cancer protein and standard immunoassays. Proteomics and separation techniques also allow for quantification of expression.
Expression Monitoring to Identify Compounds that Modify Gene Expression
In one embodiment, gene expression monitoring, i.e., an expression profile, is monitored simultaneously for a number of entities. Such profiles will typically involve one or more of the genes of
Expression monitoring is performed to identify compounds that modify the expression of one or more cancer-associated sequences, e.g., a polynucleotide sequence set out in
In one embodiment, high throughput screening methods involve providing a library containing a large number of potential therapeutic compounds (candidate compounds). Such “combinatorial chemical libraries” are then screened in one or more assays to identify those library members (particular chemical species or subclasses) that display a desired characteristic activity. The compounds thus identified can serve as conventional “lead compounds,” as compounds for screening, or as therapeutics.
In certain embodiments, combinatorial libraries of potential modulators are screened for an ability to bind to a cancer polypeptide or to modulate activity. Conventionally, new chemical entities with useful properties are generated by identifying a chemical compound (called a “lead compound”) with some desirable property or activity, e.g., inhibiting activity, creating variants of the lead compound, and evaluating the property and activity of those variant compounds. Often, high throughput screening (HTS) methods are employed for such an analysis.
As noted above, gene expression monitoring is conveniently used to test candidate modulators (e.g., protein, nucleic acid or small molecule). After the candidate agent has been added and the cells allowed to incubate for a period, the sample containing a target sequence to be analyzed is, e.g., added to a biochip.
If required, the target sequence is prepared using known techniques. For example, a sample is treated to lyse the cells, using known lysis buffers, electroporation, etc., with purification and/or amplification such as PCR performed as appropriate. For example, an in vitro transcription with labels covalently attached to the nucleotides is performed. Generally, the nucleic acids are labeled with biotin-FITC or PE, or with cy3 or cy5.
The target sequence can be labeled with, e.g., a fluorescent, a chemiluminescent, a chemical, or a radioactive signal, to provide a means of detecting the target sequence's specific binding to a probe. The label also can be an enzyme, such as alkaline phosphatase or horseradish peroxidase, which when provided with an appropriate substrate produces a product that is detected. Alternatively, the label is a labeled compound or small molecule, such as an enzyme inhibitor, that binds but is not catalyzed or altered by the enzyme. The label also can be a moiety or compound, such as, an epitope tag or biotin which specifically binds to streptavidin. For the example of biotin, the streptavidin is labeled as described above, thereby, providing a detectable signal for the bound target sequence. Unbound labeled streptavidin is typically removed prior to analysis.
As will be appreciated by those in the art, these assays can be direct hybridization assays or can comprise “sandwich assays”, which include the use of multiple probes, as is generally outlined in U.S. Pat. Nos. 5,681,702; 5,597,909; 5,545,730; 5,594,117; 5,591,584; 5,571,670; 5,580,731; 5,571,670; 5,591,584; 5,624,802; 5,635,352; 5,594,118; 5,359,100; 5,124,246; and 5,681,697. In this embodiment, in general, the target nucleic acid is prepared as outlined above, and then added to the biochip comprising a plurality of nucleic acid probes, under conditions that allow the formation of a hybridization complex.
A variety of hybridization conditions are used in the present invention, including high, moderate and low stringency conditions as outlined above. The assays are generally run under stringency conditions which allow formation of the label probe hybridization complex only in the presence of target. Stringency can be controlled by altering a step parameter that is a thermodynamic variable, including, but not limited to, temperature, formamide concentration, salt concentration, chaotropic salt concentration pH, organic solvent concentration, etc. These parameters may also be used to control non-specific binding, as is generally outlined in U.S. Pat. No. 5,681,697. Thus, it can be desirable to perform certain steps at higher stringency conditions to reduce non-specific binding.
The reactions outlined herein can be accomplished in a variety of ways. Components of the reaction can be added simultaneously, or sequentially, in different orders, with preferred embodiments outlined below. In addition, the reaction may include a variety of other reagents. These include salts, buffers, neutral proteins, e.g. albumin, detergents, etc. which can be used to facilitate optimal hybridization and detection, and/or reduce nonspecific or background interactions. Reagents that otherwise improve the efficiency of the assay, such as protease inhibitors, nuclease inhibitors, anti-microbial agents, etc., may also be used as appropriate, depending on the sample preparation methods and purity of the target. The assay data are analyzed to determine the expression levels of individual genes, and changes in expression levels as between states, forming a gene expression profile.
Biological Activity-Related Assays
The invention provides methods to identify or screen for a compound that modulates the activity of a cancer-related gene or protein of the invention. The methods comprise adding a test compound, as defined above, to a cell comprising a cancer protein of the invention. The cells contain a recombinant nucleic acid that encodes a cancer protein of the invention. In another embodiment, a library of candidate agents is tested on a plurality of cells.
In one aspect, the assays are evaluated in the presence or absence or previous or subsequent exposure of physiological signals, e.g. hormones, antibodies, peptides, antigens, cytokines, growth factors, action potentials, pharmacological agents including chemotherapeutics, radiation, carcinogenics, or other cells (i.e., cell-cell contacts). In another example, the determinations are made at different stages of the cell cycle process. In this way, compounds that modulate genes or proteins of the invention are identified. Compounds with pharmacological activity are able to enhance or interfere with the activity of the cancer protein of the invention. Once identified, similar structures are evaluated to identify critical structural features of the compound.
In one embodiment, a method of modulating (e.g., inhibiting) cancer cell division is provided; the method comprises administration of a cancer modulator. In another embodiment, a method of modulating (e.g., inhibiting) cancer is provided; the method comprises administration of a cancer modulator. In a further embodiment, methods of treating cells or individuals with cancer are provided; the method comprises administration of a cancer modulator.
In one embodiment, a method for modulating the status of a cell that expresses a gene of the invention is provided. As used herein status comprises such art-accepted parameters such as growth, proliferation, survival, function, apoptosis, senescence, location, enzymatic activity, signal transduction, etc. of a cell. In one embodiment, a cancer inhibitor is an antibody as discussed above. In another embodiment, the cancer inhibitor is an antisense molecule, siRNA oligomer or shRNA (delivered as DNA or by infection with a virus including, but not limited to, adenovirus, adeno-associated virus, lentivirus or retrovirus). A variety of cell growth, proliferation, and metastasis assays are known to those of skill in the art, as described herein.
High Throughput Screening to Identify Modulators
The assays to identify suitable modulators are amenable to high throughput screening. Preferred assays thus detect enhancement or inhibition of cancer gene transcription, inhibition or enhancement of polypeptide expression, and inhibition or enhancement of polypeptide activity.
In one embodiment, modulators evaluated in high throughput screening methods are proteins, often naturally occurring proteins or fragments of naturally occurring proteins. Thus, e.g., cellular extracts containing proteins, or random or directed digests of proteinaceous cellular extracts, are used. In this way, libraries of proteins are made for screening in the methods of the invention. Particularly preferred in this embodiment are libraries of bacterial, fungal, viral, and mammalian proteins, with the latter being preferred, and human proteins being especially preferred. Particularly useful test compound will be directed to the class of proteins to which the target belongs, e.g., substrates for enzymes, or ligands and receptors.
Use of Soft Agar Growth and Colony Formation to Identify and Characterize Modulators
Normal cells require a solid substrate to attach and grow. When cells are transformed, they lose this phenotype and grow detached from the substrate. For example, transformed cells can grow in stirred suspension culture or suspended in semi-solid media, such as semi-solid or soft agar. The transformed cells, when transfected with tumor suppressor genes, can regenerate normal phenotype and once again require a solid substrate to attach to and grow. Soft agar growth or colony formation assays are used to identify modulators of cancer sequences, which when expressed in host cells, inhibit abnormal cellular proliferation and transformation. A modulator reduces or eliminates the host cells' ability to grow suspended in solid or semisolid media, such as agar.
Techniques for soft agar growth or colony formation in suspension assays are described in Freshney, Culture of Animal Cells a Manual of Basic Technique (3rd ed., 1994). See also, the methods section of Garkavtsev et al. (1996), supra.
Evaluation of Contact Inhibition and Growth Density Limitation to Identify and Characterize Modulators
Normal cells typically grow in a flat and organized pattern in cell culture until they touch other cells. When the cells touch one another, they are contact inhibited and stop growing. Transformed cells, however, are not contact inhibited and continue to grow to high densities in disorganized foci. Thus, transformed cells grow to a higher saturation density than corresponding normal cells. This is detected morphologically by the formation of a disoriented monolayer of cells or cells in foci. Alternatively, labeling index with (3H)-thymidine at saturation density is used to measure density limitation of growth, similarly an MTT or Alamar blue assay will reveal proliferation capacity of cells and the ability of modulators to affect same. See Freshney (1994), supra. Transformed cells, when transfected with tumor suppressor genes, can regenerate a normal phenotype and become contact inhibited and would grow to a lower density.
In this assay, labeling index with (3H)-thymidine at saturation density is a preferred method of measuring density limitation of growth. Transformed host cells are transfected with a cancer-associated sequence and are grown for 24 hours at saturation density in non-limiting medium conditions. The percentage of cells labeling with (3H)-thymidine is determined by incorporated cpm.
Contact independent growth is used to identify modulators of cancer sequences, which had led to abnormal cellular proliferation and transformation. A modulator reduces or eliminates contact independent growth, and returns the cells to a normal phenotype.
Evaluation of Growth Factor or Serum Dependence to Identify and Characterize Modulators
Transformed cells have lower serum dependence than their normal counterparts (see, e.g., Temin, J. Natl. Cancer Inst. 37:167-175 (1966); Eagle et al., J. Exp. Med. 131:836-879 (1970)); Freshney, supra. This is in part due to release of various growth factors by the transformed cells. The degree of growth factor or serum dependence of transformed host cells can be compared with that of control. For example, growth factor or serum dependence of a cell is monitored in methods to identify and characterize compounds that modulate cancer-associated sequences of the invention.
Use of Tumor-Specific Marker Levels to Identify and Characterize Modulators
Tumor cells release an increased amount of certain factors (hereinafter “tumor specific markers”) than their normal counterparts. For example, plasminogen activator (PA) is released from human glioma at a higher level than from normal brain cells (see, e.g., Gullino, Angiogenesis, Tumor Vascularization, and Potential Interference with Tumor Growth, in Biological Responses in Cancer, pp. 178-184 (Mihich (ed.) 1985)). Similarly, Tumor Angiogenesis Factor (TAF) is released at a higher level in tumor cells than their normal counterparts. See, e.g., Folkman, Angiogenesis and Cancer, Sem. Cancer Biol. (1992)), while bFGF is released from endothelial tumors (Ensoli, B et al.).
Various techniques which measure the release of these factors are described in Freshney (1994), supra. Also, see, Unkless et al., J. Biol. Chem. 249:4295-4305 (1974); Strickland & Beers, J. Biol. Chem. 251:5694-5702 (1976); Whur et al., Br. J. Cancer 42:305 312 (1980); Gullino, Angiogenesis, Tumor Vascularization, and Potential Interference with Tumor Growth, in Biological Responses in Cancer, pp. 178-184 (Mihich (ed.) 1985); Freshney, Anticancer Res. 5:111-130 (1985). For example, tumor specific marker levels are monitored in methods to identify and characterize compounds that modulate cancer-associated sequences of the invention.
Invasiveness into Matrigel to Identify and Characterize Modulators
The degree of invasiveness into Matrigel or an extracellular matrix constituent can be used as an assay to identify and characterize compounds that modulate cancer associated sequences. Tumor cells exhibit a positive correlation between malignancy and invasiveness of cells into Matrigel or some other extracellular matrix constituent. In this assay, tumorigenic cells are typically used as host cells. Expression of a tumor suppressor gene in these host cells would decrease invasiveness of the host cells. Techniques described in Cancer Res. 1999; 59:6010; Freshney (1994), supra, can be used. Briefly, the level of invasion of host cells is measured by using filters coated with Matrigel or some other extracellular matrix constituent. Penetration into the gel, or through to the distal side of the filter, is rated as invasiveness, and rated histologically by number of cells and distance moved, or by prelabeling the cells with 125I and counting the radioactivity on the distal side of the filter or bottom of the dish. See, e.g., Freshney (1984), supra.
Evaluation of Tumor Growth In Vivo to Identify and Characterize Modulators
Effects of cancer-associated sequences on cell growth are tested in transgenic or immune-suppressed organisms. Transgenic organisms are prepared in a variety of art-accepted ways. For example, knock-out transgenic organisms, e.g., mammals such as mice, are made, in which a cancer gene is disrupted or in which a cancer gene is inserted. Knock-out transgenic mice are made by insertion of a marker gene or other heterologous gene into the endogenous cancer gene site in the mouse genome via homologous recombination. Such mice can also be made by substituting the endogenous cancer gene with a mutated version of the cancer gene, or by mutating the endogenous cancer gene, e.g., by exposure to carcinogens.
To prepare transgenic chimeric animals, e.g., mice, a DNA construct is introduced into the nuclei of embryonic stem cells. Cells containing the newly engineered genetic lesion are injected into a host mouse embryo, which is re-implanted into a recipient female. Some of these embryos develop into chimeric mice that possess germ cells some of which are derived from the mutant cell line. Therefore, by breeding the chimeric mice it is possible to obtain a new line of mice containing the introduced genetic lesion (see, e.g., Capecchi et al., Science 244:1288 (1989)). Chimeric mice can be derived according to U.S. Pat. No. 6,365,797, issued 2 Apr. 2002; U.S. Pat. No. 6,107,540 issued 22 Aug. 2000; Hogan et al., Manipulating the Mouse Embryo: A laboratory Manual, Cold Spring Harbor Laboratory (1988) and Teratocarcinomas and Embryonic Stem Cells: A Practical Approach, Robertson, ed., IRL Press, Washington, D.C., (1987).
Alternatively, various immune-suppressed or immune-deficient host animals can be used. For example, a genetically athymic “nude” mouse (see, e.g., Giovanella et al., J. Natl. Cancer Inst. 52:921 (1974)), a SCID mouse, a thymectornized mouse, or an irradiated mouse (see, e.g., Bradley et al., Br. J. Cancer 38:263 (1978); Selby et al., Br. J. Cancer 41:52 (1980)) can be used as a host. Transplantable tumor cells (typically about 106 cells) injected into isogenic hosts produce invasive tumors in a high proportion of cases, while normal cells of similar origin will not. In hosts which developed invasive tumors, cells expressing cancer-associated sequences are injected subcutaneously or orthotopically. Mice are then separated into groups, including control groups and treated experimental groups) e.g. treated with a modulator). After a suitable length of time, preferably 4-8 weeks, tumor growth is measured (e.g., by volume or by its two largest dimensions, or weight) and compared to the control. Tumors that have statistically significant reduction (using, e.g., Student's T test) are said to have inhibited growth.
In Vitro Assays to Identify and Characterize Modulators
Assays to identify compounds with modulating activity can be performed in vitro. For example, a cancer polypeptide is first contacted with a potential modulator and incubated for a suitable amount of time, e.g., from 0.5 to 48 hours. In one embodiment, the cancer polypeptide levels are determined in vitro by measuring the level of protein or mRNA. The level of protein is measured using immunoassays such as Western blotting, ELISA and the like with an antibody that selectively binds to the cancer polypeptide or a fragment thereof. For measurement of mRNA, amplification, e.g., using PCR, LCR, or hybridization assays, e.g., Northern hybridization, RNAse protection, dot blotting, are preferred. The level of protein or mRNA is detected using directly or indirectly labeled detection agents, e.g., fluorescently or radioactively labeled nucleic acids, radioactively or enzymatically labeled antibodies, and the like, as described herein.
Alternatively, a reporter gene system can be devised using a cancer protein promoter operably linked to a reporter gene such as luciferase, green fluorescent protein, CAT, or P-gal. The reporter construct is typically transfected into a cell. After treatment with a potential modulator, the amount of reporter gene transcription, translation, or activity is measured according to standard techniques known to those of skill in the art (Davis G F, supra; Gonzalez, J. & Negulescu, P. Curr. Opin. Biotechnol. 1998: 9:624).
As outlined above, in vitro screens are done on individual genes and gene products. That is, having identified a particular differentially expressed gene as important in a particular state, screening of modulators of the expression of the gene or the gene product itself is performed.
In one embodiment, screening for modulators of expression of specific gene(s) is performed. Typically, the expression of only one or a few genes is evaluated. In another embodiment, screens are designed to first find compounds that bind to differentially expressed proteins. These compounds are then evaluated for the ability to modulate differentially expressed activity. Moreover, once initial candidate compounds are identified, variants can be further screened to better evaluate structure activity relationships.
Binding Assays to Identify and Characterize Modulators
In binding assays in accordance with the invention, a purified or isolated gene product of the invention is generally used. For example, antibodies are generated to a protein of the invention, and immunoassays are run to determine the amount and/or location of protein. Alternatively, cells comprising the cancer proteins are used in the assays.
Thus, the methods comprise combining a cancer protein of the invention and a candidate compound such as a ligand, and determining the binding of the compound to the cancer protein of the invention. Preferred embodiments utilize the human cancer protein; animal models of human disease of can also be developed and used. Also, other analogous mammalian proteins also can be used as appreciated by those of skill in the art. Moreover, in some embodiments variant or derivative cancer proteins are used.
Generally, the cancer protein of the invention, or the ligand, is non-diffusibly bound to an insoluble support. The support can, e.g., be one having isolated sample receiving areas (a microtiter plate, an array, etc.). The insoluble supports can be made of any composition to which the compositions can be bound, is readily separated from soluble material, and is otherwise compatible with the overall method of screening. The surface of such supports can be solid or porous and of any convenient shape.
Examples of suitable insoluble supports include microtiter plates, arrays, membranes and beads. These are typically made of glass, plastic (e.g., polystyrene), polysaccharide, nylon, nitrocellulose, or Teflon™, etc. Microtiter plates and arrays are especially convenient because a large number of assays can be carried out simultaneously, using small amounts of reagents and samples. The particular manner of binding of the composition to the support is not crucial so long as it is compatible with the reagents and overall methods of the invention, maintains the activity of the composition and is nondiffusable. Preferred methods of binding include the use of antibodies which do not sterically block either the ligand binding site or activation sequence when attaching the protein to the support, direct binding to “sticky” or ionic supports, chemical crosslinking, the synthesis of the protein or agent on the surface, etc. Following binding of the protein or ligand/binding agent to the support, excess unbound material is removed by washing. The sample receiving areas may then be blocked through incubation with bovine serum albumin (BSA), casein or other innocuous protein or other moiety.
Once a cancer protein of the invention is bound to the support, and a test compound is added to the assay. Alternatively, the candidate binding agent is bound to the support and the cancer protein of the invention is then added. Binding agents include specific antibodies, non-natural binding agents identified in screens of chemical libraries, peptide analogs, etc.
Of particular interest are assays to identify agents that have a low toxicity for human cells. A wide variety of assays can be used for this purpose, including proliferation assays, cAMP assays, labeled in vitro protein-protein binding assays, electrophoretic mobility shift assays, immunoassays for protein binding, functional assays (phosphorylation assays, etc.) and the like.
A determination of binding of the test compound (ligand, binding agent, modulator, etc.) to a cancer protein of the invention can be done in a number of ways. The test compound can be labeled, and binding determined directly, e.g., by attaching all or a portion of the cancer protein of the invention to a solid support, adding a labeled candidate compound (e.g., a fluorescent label), washing off excess reagent, and determining whether the label is present on the solid support. Various blocking and washing steps can be utilized as appropriate.
In certain embodiments, only one of the components is labeled, e.g., a protein of the invention or ligands labeled. Alternatively, more than one component is labeled with different labels, e.g., I125, for the proteins and a fluorophor for the compound. Proximity reagents, e.g., quenching or energy transfer reagents are also useful.
Competitive Binding to Identify and Characterize Modulators
In one embodiment, the binding of the “test compound” is determined by competitive binding assay with a “competitor.” The competitor is a binding moiety that binds to the target molecule (e.g., a cancer protein of the invention). Competitors include compounds such as antibodies, peptides, binding partners, ligands, etc. Under certain circumstances, the competitive binding between the test compound and the competitor displaces the test compound. In one embodiment, the test compound is labeled. Either the test compound, the competitor, or both, is added to the protein for a time sufficient to allow binding. Incubations are performed at a temperature that facilitates optimal activity, typically between four and 40° C. Incubation periods are typically optimized, e.g., to facilitate rapid high throughput screening; typically between zero and one hour will be sufficient. Excess reagent is generally removed or washed away. The second component is then added, and the presence or absence of the labeled component is followed, to indicate binding.
In one embodiment, the competitor is added first, followed by the test compound. Displacement of the competitor is an indication that the test compound is binding to the cancer protein and thus is capable of binding to, and potentially modulating, the activity of the cancer protein. In this embodiment, either component can be labeled. Thus, e.g., if the competitor is labeled, the presence of label in the post-test compound wash solution indicates displacement by the test compound. Alternatively, if the test compound is labeled, the presence of the label on the support indicates displacement.
In an alternative embodiment, the test compound is added first, with incubation and washing, followed by the competitor. The absence of binding by the competitor indicates that the test compound binds to the cancer protein with higher affinity than the competitor. Thus, if the test compound is labeled, the presence of the label on the support, coupled with a lack of competitor binding, indicates that the test compound binds to and thus potentially modulates the cancer protein of the invention.
Accordingly, the competitive binding methods comprise differential screening to identity agents that are capable of modulating the activity of the cancer proteins of the invention. In this embodiment, the methods comprise combining a cancer protein and a competitor in a first sample. A second sample comprises a test compound, the cancer protein, and a competitor. The binding of the competitor is determined for both samples, and a change, or difference in binding between the two samples indicates the presence of an agent capable of binding to the cancer protein and potentially modulating its activity. That is, if the binding of the competitor is different in the second sample relative to the first sample, the agent is capable of binding to the cancer protein.
Alternatively, differential screening is used to identify drug candidates that bind to the native cancer protein, but cannot bind to modified cancer proteins. For example the structure of the cancer protein is modeled and used in rational drug design to synthesize agents that interact with that site, agents which generally do not bind to site-modified proteins. Moreover, such drug candidates that affect the activity of a native cancer protein are also identified by screening drugs for the ability to either enhance or reduce the activity of such proteins.
Positive controls and negative controls can be used in the assays. Preferably control and test samples are performed in at least triplicate to obtain statistically significant results. Incubation of all samples occurs for a time sufficient to allow for the binding of the agent to the protein. Following incubation, samples are washed free of non-specifically bound material and the amount of bound, generally labeled agent determined. For example, where a radiolabel is employed, the samples can be counted in a scintillation counter to determine the amount of bound compound.
A variety of other reagents can be included in the screening assays. These include reagents like salts, neutral proteins, e.g. albumin, detergents, etc. which are used to facilitate optimal protein-protein binding and/or reduce non-specific or background interactions. Also reagents that otherwise improve the efficiency of the assay, such as protease inhibitors, nuclease inhibitors, anti-microbial agents, etc., can be used. The mixture of components is added in an order that provides for the requisite binding.
Use of Polynucleotides to Down-Regulate or Inhibit a Protein of the Invention.
Polynucleotide modulators of cancer can be introduced into a cell containing the target nucleotide sequence by formation of a conjugate with a ligand-binding molecule, as described in WO 91/04753. Suitable ligand-binding molecules include, but are not limited to, cell surface receptors, growth factors, other cytokines, or other ligands that bind to cell surface receptors. Preferably, conjugation of the ligand binding molecule does not substantially interfere with the ability of the ligand binding molecule to bind to its corresponding molecule or receptor, or block entry of the sense or antisense oligonucleotide or its conjugated version into the cell. Alternatively, a polynucleotide modulator of cancer can be introduced into a cell containing the target nucleic acid sequence, e.g., by formation of a polynucleotide-lipid complex, as described in WO 90/10448. It is understood that the use of antisense molecules or knock out and knock in models may also be used in screening assays as discussed above, in addition to methods of treatment.
Inhibitory and Antisense Nucleotides
In certain embodiments, the activity of a cancer-associated protein is down-regulated, or entirely inhibited, by the use of antisense polynucleotide or inhibitory small nuclear RNA (snRNA), i.e., a nucleic acid complementary to, and which can preferably hybridize specifically to, a coding mRNA nucleic acid sequence, e.g., a cancer protein of the invention, mRNA, or a subsequence thereof. Binding of the antisense polynucleotide to the mRNA reduces the translation and/or stability of the mRNA.
In the context of this invention, antisense polynucleotides can comprise naturally occurring nucleotides, or synthetic species formed from naturally occurring subunits or their close homologs. Antisense polynucleotides may also have altered sugar moieties or inter-sugar linkages. Exemplary among these are the phosphorothioate and other sulfur containing species which are known for use in the art. Analogs are comprised by this invention so long as they function effectively to hybridize with nucleotides of the invention. See, e.g., Isis Pharmaceuticals, Carlsbad, Calif.; Sequitor, Inc., Natick, Mass.
Such antisense polynucleotides can readily be synthesized using recombinant means, or can be synthesized in vitro. Equipment for such synthesis is sold by several vendors, including Applied Biosystems. The preparation of other oligonucleotides such as phosphorothioates and alkylated derivatives is also well known to those of skill in the art.
Antisense molecules as used herein include antisense or sense oligonucleotides. Sense oligonucleotides can, e.g., be employed to block transcription by binding to the anti-sense strand. The antisense and sense oligonucleotide comprise a single stranded nucleic acid sequence (either RNA or DNA) capable of binding to target mRNA (sense) or DNA (antisense) sequences for cancer molecules. Antisense or sense oligonucleotides, according to the present invention, comprise a fragment generally at least about 12 nucleotides, preferably from about 12 to 30 nucleotides. The ability to derive an antisense or a sense oligonucleotide, based upon a cDNA sequence encoding a given protein is described in, e.g., Stein &Cohen (Cancer Res. 48:2659 (1988 and van der Krol et al. (BioTechniques 6:958 (1988)).
In addition to antisense polynucleotides, ribozymes can be used to target and inhibit transcription of cancer-associated nucleotide sequences. A ribozyme is an RNA molecule that catalytically cleaves other RNA molecules. Different kinds of ribozymes have been described, including group I ribozymes, hammerhead ribozymes, hairpin ribozymes, RNase P, and axhead ribozymes (see, e.g., Castanotto et al., Adv. in Pharmacology 25: 289-317 (1994) for a general review of the properties of different ribozymes).
The general features of hairpin ribozymes are described, e.g., in Hampel et al., Nucl. Acids Res. 18:299-304 (1990); European Patent Publication No. 0360257; U.S. Pat. No. 5,254,678. Methods of preparing are well known to those of skill in the art (see, e.g., WO 94/26877; Ojwang et al., Proc. Natl. Acad. Sci. USA 90:6340-6344 (1993); Yamada et al., Human Gene Therapy 1:39-45 (1994); Leavitt et al., Proc. Natl. Acad. Sci. USA 92:699-703 (1995); Leavitt et al., Human Gene Therapy 5: 1151-120 (1994); and Yamada et al., Virology 205: 121-126 (1994)).
Use of Modulators in Phenotypic Screening
In one embodiment, a test compound is administered to a population of cancer cells, which have an associated cancer expression profile. By “administration” or “contacting” herein is meant that the modulator is added to the cells in such a manner as to allow the modulator to act upon the cell, whether by uptake and intracellular action, or by action at the cell surface. In some embodiments, a nucleic acid encoding a proteinaceous agent (i.e., a peptide) is put into a viral construct such as an adenoviral or retroviral construct, and added to the cell, such that expression of the peptide agent is accomplished, e.g., PCT US97/01019. Regulatable gene therapy systems can also be used. Once the modulator has been administered to the cells, the cells are washed if desired and are allowed to incubate under preferably physiological conditions for some period. The cells are then harvested and a new gene expression profile is generated. Thus, e.g., cancer tissue is screened for agents that modulate, e.g., induce or suppress, the cancer phenotype. A change in at least one gene, preferably many, of the expression profile indicates that the agent has an effect on cancer activity. Similarly, altering a biological function or a signaling pathway is indicative of modulator activity. By defining such a signature for the cancer phenotype, screens for new drugs that alter the phenotype are devised. With this approach, the drug target need not be known and need not be represented in the original gene/protein expression screening platform, nor does the level of transcript for the target protein need to change. The modulator inhibiting function will serve as a surrogate marker.
As outlined above, screens are done to assess genes or gene products. That is, having identified a particular differentially expressed gene as important in a particular state, screening of modulators of either the expression of the gene or the gene product itself is performed.
Use of Modulators to Affect Peptides of the Invention
Measurements of cancer polypeptide activity, or of the cancer phenotype are performed using a variety of assays. For example, the effects of modulators upon the function of a cancer polypeptide(s) are measured by examining parameters described above. A physiological change that affects activity is used to assess the influence of a test compound on the polypeptides of this invention. When the functional outcomes are determined using intact cells or animals, a variety of effects can be assesses such as, in the case of a cancer associated with solid tumors, tumor growth, tumor metastasis, neovascularization, hormone release, transcriptional changes to both known and uncharacterized genetic markers (e.g., by Northern blots), changes in cell metabolism such as cell growth or pH changes, and changes in intracellular second messengers such as cGNIP.
Methods of Identifying Characterizing Cancer-Associated Sequences
Expression of various gene sequences is correlated with cancer. Accordingly, disorders based on mutant or variant cancer genes are determined. In one embodiment, the invention provides methods for identifying cells containing variant cancer genes, e.g., determining the presence of, all or part, the sequence of at least one endogenous cancer gene in a cell. This is accomplished using any number of sequencing techniques. The invention comprises methods of identifying the cancer genotype of an individual, e.g., determining all or part of the sequence of at least one gene of the invention in the individual. This is generally done in at least one tissue of the individual, e.g., a tissue set forth in Table I, and may include the evaluation of a number of tissues or different samples of the same tissue. The method may include comparing the sequence of the sequenced gene to a known cancer gene, i.e., a wild-type gene to determine the presence of family members, homologies, mutations or variants. The sequence of all or part of the gene can then be compared to the sequence of a known cancer gene to determine if any differences exist. This is done using any number of known homology programs, such as BLAST, Bestfit, etc. The presence of a difference in the sequence between the cancer gene of the patient and the known cancer gene correlates with a disease state or a propensity for a disease state, as outlined herein.
In a preferred embodiment, the cancer genes are used as probes to determine the number of copies of the cancer gene in the genome. The cancer genes are used as probes to determine the chromosomal localization of the cancer genes. Information such as chromosomal localization finds use in providing a diagnosis or prognosis in particular when chromosomal abnormalities such as translocations, and the like are identified in the cancer gene locus.
XII.) RNAi and Therapeutic Use of Small Interfering RNA (siRNAs)
The present invention is also directed towards siRNA oligonucleotides, particularly double stranded RNAs encompassing at least a fragment of the 24P4C12 coding region or 5′ UTR regions, or complement, or any antisense oligonucleotide specific to the 24P4C12 sequence. In one embodiment such oligonucleotides are used to elucidate a function of 24P4C12, or are used to screen for or evaluate modulators of 24P4C12 function or expression. In another embodiment, gene expression of 24P4C12 is reduced by using siRNA transfection and results in significantly diminished proliferative capacity of transformed cancer cells that endogenously express the antigen; cells treated with specific 24P4C12 siRNAs show reduced survival as measured, e.g., by a metabolic readout of cell viability, correlating to the reduced proliferative capacity. Thus, 24P4C12 siRNA compositions comprise siRNA (double stranded RNA) that correspond to the nucleic acid ORF sequence of the 24P4C12 protein or subsequences thereof; these subsequences are generally 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 or more than 35 contiguous RNA nucleotides in length and contain sequences that are complementary and non-complementary to at least a portion of the mRNA coding sequence In a preferred embodiment, the subsequences are 19-25 nucleotides in length, most preferably 21-23 nucleotides in length.
RNA interference is a novel approach to silencing genes in vitro and in vivo, thus small double stranded RNAs (siRNAs) are valuable therapeutic agents. The power of siRNAs to silence specific gene activities has now been brought to animal models of disease and is used in humans as well. For example, hydrodynamic infusion of a solution of siRNA into a mouse with a siRNA against a particular target has been proven to be therapeutically effective.
The pioneering work by Song et al. indicates that one type of entirely natural nucleic acid, small interfering RNAs (siRNAs), served as therapeutic agents even without further chemical modification (Song, E., et al. “RNA interference targeting Fas protects mice from fulminant hepatitis” Nat. Med. 9(3): 347-51 (2003)). This work provided the first in vivo evidence that infusion of siRNAs into an animal could alleviate disease. In that case, the authors gave mice injections of siRNA designed to silence the FAS protein (a cell death receptor that when over-activated during inflammatory response induces hepatocytes and other cells to die). The next day, the animals were given an antibody specific to Fas. Control mice died of acute liver failure within a few days, while over 80% of the siRNA-treated mice remained free from serious disease and survived. About 80% to 90% of their liver cells incorporated the naked siRNA oligonucleotides. Furthermore, the RNA molecules functioned for 10 days before losing effect after 3 weeks.
For use in human therapy, siRNA is delivered by efficient systems that induce long-lasting RNAi activity. A major caveat for clinical use is delivering siRNAs to the appropriate cells. Hepatocytes seem to be particularly receptive to exogenous RNA. Today, targets located in the liver are attractive because liver is an organ that can be readily targeted by nucleic acid molecules and viral vectors. However, other tissue and organs targets are preferred as well.
Formulations of siRNAs with compounds that promote transit across cell membranes are used to improve administration of siRNAs in therapy. Chemically modified synthetic siRNA, that are resistant to nucleases and have serum stability have concomitant enhanced duration of RNAi effects, are an additional embodiment.
Thus, siRNA technology is a therapeutic for human malignancy by delivery of siRNA molecules directed to 24P4C12 to individuals with the cancers, such as those listed in Table 1. Such administration of siRNAs leads to reduced growth of cancer cells expressing 24P4C12, and provides an anti-tumor therapy, lessening the morbidity and/or mortality associated with malignancy. In another embodiment, siRNA is delivered by a virus as shRNA (short hairpin RNA). This enablement allows stable expression of the shRNA in cells both in vitro and in vivo. The shRNA may be delivered by viruses including, but not limited to, adenovirus, adeno-associated virus, lentivirus and retrovirus. Such systems allow for either viral DNA transfection or viral particles to infect cells to achieve stable expression of shRNAs, and stable suppression of cancer-associated genes such as 24P4C12.
The effectiveness of this modality of gene product knockdown is significant when measured in vitro or in vivo. Effectiveness in vitro is readily demonstrable through application of siRNAs or shRNA by DNA plasmid or virus to cells in culture (as described above) or to aliquots of cancer patient biopsies when in vitro methods are used to detect the reduced expression of 24P4C12 protein.
XIII.) Kits/Articles of Manufacture
For use in the laboratory, prognostic, prophylactic, diagnostic and therapeutic applications described herein, kits are within the scope of the invention. Such kits can comprise a carrier, package, or container that is compartmentalized to receive one or more containers such as vials, tubes, and the like, each of the container(s) comprising one of the separate elements to be used in the method, along with a label or insert comprising instructions for use, such as a use described herein. For example, the container(s) can comprise a probe that is or can be detectably labeled. Such probe can be an antibody or polynucleotide specific for a protein or a gene or message of the invention, respectively. Where the method utilizes nucleic acid hybridization to detect the target nucleic acid, the kit can also have containers containing nucleotide(s) for amplification of the target nucleic acid sequence. Kits can comprise a container comprising a reporter, such as a biotin-binding protein, such as avidin or streptavidin, bound to a reporter molecule, such as an enzymatic, fluorescent, or radioisotope label; such a reporter can be used with, e.g., a nucleic acid or antibody. The kit can include all or part of the amino acid sequences in
The kit of the invention will typically comprise the container described above and one or more other containers associated therewith that comprise materials desirable from a commercial and user standpoint, including buffers, diluents, filters, needles, syringes; carrier, package, container, vial and/or tube labels listing contents and/or instructions for use, and package inserts with instructions for use.
A label can be present on or with the container to indicate that the composition is used for a specific therapy or non-therapeutic application, such as a prognostic, prophylactic, diagnostic or laboratory application, and can also indicate directions for either in vivo or in vitro use, such as those described herein. Directions and or other information can also be included on an insert(s) or label(s) which is included with or on the kit. The label can be on or associated with the container. A label a can be on a container when letters, numbers or other characters forming the label are molded or etched into the container itself; a label can be associated with a container when it is present within a receptacle or carrier that also holds the container, e.g., as a package insert. The label can indicate that the composition is used for diagnosing, treating, prophylaxing or prognosing a condition, such as a neoplasia of a tissue set forth in Table I.
The terms “kit” and “article of manufacture” can be used as synonyms.
In another embodiment of the invention, an article(s) of manufacture containing compositions, such as amino acid sequence(s), small molecule(s), nucleic acid sequence(s), and/or antibody(s), e.g., materials useful for the diagnosis, prognosis, prophylaxis and/or treatment of neoplasias of tissues such as those set forth in Table I is provided. The article of manufacture typically comprises at least one container and at least one label. Suitable containers include, for example, bottles, vials, syringes, and test tubes. The containers can be formed from a variety of materials such as glass, metal or plastic. The container can hold amino acid sequence(s), small molecule(s), nucleic acid sequence(s), cell population(s) and/or antibody(s). In one embodiment, the container holds a polynucleotide for use in examining the mRNA expression profile of a cell, together with reagents used for this purpose. In another embodiment a container comprises an antibody, binding fragment thereof or specific binding protein for use in evaluating protein expression of 24P4C12 in cells and tissues, or for relevant laboratory, prognostic, diagnostic, prophylactic and therapeutic purposes; indications and/or directions for such uses can be included on or with such container, as can reagents and other compositions or tools used for these purposes. In another embodiment, a container comprises materials for eliciting a cellular or humoral immune response, together with associated indications and/or directions. In another embodiment, a container comprises materials for adoptive immunotherapy, such as cytotoxic T cells (CTL) or helper T cells (HTL), together with associated indications and/or directions; reagents and other compositions or tools used for such purpose can also be included.
The container can alternatively hold a composition that is effective for treating, diagnosis, prognosing or prophylaxing a condition and can have a sterile access port (for example the container can be an intravenous solution bag or a vial having a stopper pierceable by a hypodermic injection needle). The active agents in the composition can be an antibody capable of specifically binding 24P4C12 and modulating the function of 24P4C12.
The article of manufacture can further comprise a second container comprising a pharmaceutically-acceptable buffer, such as phosphate-buffered saline, Ringer's solution and/or dextrose solution. It can further include other materials desirable from a commercial and user standpoint, including other buffers, diluents, filters, stirrers, needles, syringes, and/or package inserts with indications and/or instructions for use.
Various aspects of the invention are further described and illustrated by way of the several examples that follow, none of which is intended to limit the scope of the invention.
Expression of 24P4C12 was tested in ovarian cancer patient specimens (
Expression of 24P4C12 in breast cancer patient specimens is shown in
Transcript variants are variants of mature mRNA from the same gene which arise by alternative transcription or alternative splicing. Alternative transcripts are transcripts from the same gene but start transcription at different points. Splice variants are mRNA variants spliced differently from the same transcript. In eukaryotes, when a multi-exon gene is transcribed from genomic DNA, the initial RNA is spliced to produce functional mRNA, which has only exons and is used for translation into an amino acid sequence. Accordingly, a given gene can have zero to many alternative transcripts and each transcript can have zero to many splice variants. Each transcript variant has a unique exon makeup, and can have different coding and/or non-coding (5′ or 3′ end) portions, from the original transcript. Transcript variants can code for similar or different proteins with the same or a similar function or can encode proteins with different functions, and can be expressed in the same tissue at the same time, or in different tissues at the same time, or in the same tissue at different times, or in different tissues at different times. Proteins encoded by transcript variants can have similar or different cellular or extracellular localizations, e.g., secreted versus intracellular.
Transcript variants are identified by a variety of art-accepted methods. For example, alternative transcripts and splice variants are identified by full-length cloning experiment, or by use of full-length transcript and EST sequences. First, all human ESTs were grouped into clusters which show direct or indirect identity with each other. Second, ESTs in the same cluster were further grouped into sub-clusters and assembled into a consensus sequence. The original gene sequence is compared to the consensus sequence(s) or other full-length sequences. Each consensus sequence is a potential splice variant for that gene. Even when a variant is identified that is not a full-length clone, that portion of the variant is very useful for antigen generation and for further cloning of the full-length splice variant, using techniques known in the art.
Moreover, computer programs are available in the art that identify transcript variants based on genomic sequences. Genomic-based transcript variant identification programs include FgenesH (A. Salamov and V. Solovyev, “Ab initio gene finding in Drosophila genomic DNA,” Genome Research. 2000 April; 10(4):516-22); Grail (URL at compbio.ornl.gov/Grail-bin/EmptyGrailForm) and GenScan (URL at genes.mit.edu/GENSCAN.html). For a general discussion of splice variant identification protocols see., e.g., Southan, C., A genomic perspective on human proteases, FEBS Lett. 2001 Jun. 8; 498(2-3):214-8; de Souza, S. J., et al., Identification of human chromosome 22 transcribed sequences with ORF expressed sequence tags, Proc. Natl. Acad Sci USA. 2000 Nov. 7; 97(23):12690-3.
To further confirm the parameters of a transcript variant, a variety of techniques are available in the art, such as full-length cloning, proteomic validation, PCR-based validation, and 5′ RACE validation, etc. (see e.g., Proteomic Validation: Brennan, S. O., et al., Albumin banks peninsula: a new termination variant characterized by electrospray mass spectrometry, Biochem Biophys Acta. 1999 Aug. 17; 1433(1-2):321-6; Ferranti P, et al., Differential splicing of pre-messenger RNA produces multiple forms of mature caprine alpha(s1)-casein, Eur J. Biochem. 1997 Oct. 1; 249(1):1-7. For PCR-based Validation: Wellmann S, et al., Specific reverse transcription-PCR quantification of vascular endothelial growth factor (VEGF) splice variants by LightCycler technology, Clin Chem. 2001 April; 47(4):654-60; Jia, H. P., et al., Discovery of new human beta-defensins using a genomics-based approach, Gene. 2001 Jan. 24; 263(1-2):211-8. For PCR-based and 5′ RACE Validation: Brigle, K. E., et al., Organization of the murine reduced folate carrier gene and identification of variant splice forms, Biochem Biophys Acta. 1997 Aug. 7; 1353(2): 191-8).
It is known in the art that genomic regions are modulated in cancers. When the genomic region to which a gene maps is modulated in a particular cancer, the alternative transcripts or splice variants of the gene are modulated as well. Disclosed herein is that 24P4C12 has a particular expression profile related to cancer. Alternative transcripts and splice variants of 24P4C12 may also be involved in cancers in the same or different tissues, thus serving as tumor-associated markers/antigens. Accordingly, the 24P4C12 MAbs disclosed herein also bind to the 24P4C12 variants disclosed in
A Single Nucleotide Polymorphism (SNP) is a single base pair variation in a nucleotide sequence at a specific location. At any given point of the genome, there are four possible nucleotide base pairs: A/T, C/G, G/C and T/A. Genotype refers to the specific base pair sequence of one or more locations in the genome of an individual. Haplotype refers to the base pair sequence of more than one location on the same DNA molecule (or the same chromosome in higher organisms), often in the context of one gene or in the context of several tightly linked genes. SNPs that occur on a cDNA are called cSNPs. These cSNPs may change amino acids of the protein encoded by the gene and thus change the functions of the protein. Some SNPs cause inherited diseases; others contribute to quantitative variations in phenotype and reactions to environmental factors including diet and drugs among individuals. Therefore, SNPs and/or combinations of alleles (called haplotypes) have many applications, including diagnosis of inherited diseases, determination of drug reactions and dosage, identification of genes responsible for diseases, and analysis of the genetic relationship between individuals (P. Nowotny, J. M. Kwon and A. M. Goate, “SNP analysis to dissect human traits,” Curr. Opin. Neurobiol. 2001 October; 11(5):637-641; M. Pirmohamed and B. K. Park, “Genetic susceptibility to adverse drug reactions,” Trends Pharmacol. Sci. 2001 June; 22(6):298-305; J. H. Riley, C. J. Allan, E. Lai and A. Roses, “The use of single nucleotide polymorphisms in the isolation of common disease genes,” Pharmacogenomics. 2000 February; 1(1):39-47; R. Judson, J. C. Stephens and A. Windemuth, “The predictive power of haplotypes in clinical response,” Pharmacogenomics. 2000 feb; 1(1):15-26).
SNPs are identified by a variety of art-accepted methods (P. Bean, “The promising voyage of SNP target discovery,” Am. Clin. Lab. 2001 October-November; 20(9):18-20; K. M. Weiss, “In search of human variation,” Genome Res. 1998 July; 8(7):691-697; M. M. She, “Enabling large-scale pharmacogenetic studies by high-throughput mutation detection and genotyping technologies,” Clin. Chem. 2001 February; 47(2):164-172). For example, SNPs are identified by sequencing DNA fragments that show polymorphism by gel-based methods such as restriction fragment length polymorphism (RFLP) and denaturing gradient gel electrophoresis (DGGE). They can also be discovered by direct sequencing of DNA samples pooled from different individuals or by comparing sequences from different DNA samples. With the rapid accumulation of sequence data in public and private databases, one can discover SNPs by comparing sequences using computer programs (Z. Gu, L. Hillier and P. Y. Kwok, “Single nucleotide polymorphism hunting in cyberspace,” Hum. Mutat. 1998; 12(4):221-225). SNPs can be verified and genotype or haplotype of an individual can be determined by a variety of methods including direct sequencing and high throughput microarrays (P. Y. Kwok, “Methods for genotyping single nucleotide polymorphisms,” Annu. Rev. Genomics Hum. Genet. 2001; 2:235-258; M. Kokoris, K. Dix, K. Moynihan, J. Mathis, B. Erwin, P. Grass, B. Hines and A. Duesterhoeft, “High-throughput SNP genotyping with the Masscode system,” Mol. Diagn. 2000 December; 5(4):329-340).
To express recombinant 24P4C12 and 24P4C12 variants in prokaryotic cells, the full or partial length 24P4C12 and 24P4C12 variant cDNA sequences are cloned into any one of a variety of expression vectors known in the art. The full length cDNA, or any 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more contiguous amino acids from 24P4C12, variants, or analogs thereof are used.
A. In Vitro Transcription and Translation Constructs:
pCRII: To generate 24P4C12 sense and anti-sense RNA probes for RNA in situ investigations, pCRII constructs (Invitrogen, Carlsbad Calif.) are generated encoding either all or fragments of the 24P4C12 cDNA. The pCRII vector has Sp6 and T7 promoters flanking the insert to drive the transcription of 24P4C12 RNA for use as probes in RNA in situ hybridization experiments. These probes are used to analyze the cell and tissue expression of 24P4C12 at the RNA level. Transcribed 24P4C12 RNA representing the cDNA amino acid coding region of the 24P4C12 gene is used in in vitro translation systems such as the TnT™ Coupled Reticulolysate System (Promega, Corp., Madison, Wis.) to synthesize 24P4C12 protein.
B. Bacterial Constructs:
pGEX Constructs: To generate recombinant 24P4C12 proteins in bacteria that are fused to the Glutathione S-transferase (GST) protein, all or parts of the 24P4C12 cDNA or variants are cloned into the GST-fusion vector of the pGEX family (Amersham Pharmacia Biotech, Piscataway, N.J.). These constructs allow controlled expression of recombinant 24P4C12 protein sequences with GST fused at the amino-terminus and a six histidine epitope (6X His) at the carboxyl-terminus. The GST and 6X His tags permit purification of the recombinant fusion protein from induced bacteria with the appropriate affinity matrix and allow recognition of the fusion protein with anti-GST and anti-His antibodies. The 6X His tag is generated by adding 6 histidine codons to the cloning primer at the 3′ end, e.g., of the open reading frame (ORF). A proteolytic cleavage site, such as the PreScission™ recognition site in pGEX-6P-1, may be employed such that it permits cleavage of the GST tag from 24P4C12-related protein. The ampicillin resistance gene and pBR322 origin permits selection and maintenance of the pGEX plasmids in E. coli.
pMAL Constructs: To generate, in bacteria, recombinant 24P4C12 proteins that are fused to maltose-binding protein (MBP), all or parts of the 24P4C12 cDNA protein coding sequence are fused to the MBP gene by cloning into the pMAL-c2X and pMAL-p2X vectors (New England Biolabs, Beverly, Mass.). These constructs allow controlled expression of recombinant 24P4C12 protein sequences with MBP fused at the amino-terminus and a 6X His epitope tag at the carboxyl-terminus. The MBP and 6X His tags permit purification of the recombinant protein from induced bacteria with the appropriate affinity matrix and allow recognition of the fusion protein with anti-MBP and anti-His antibodies. The 6X His epitope tag is generated by adding 6 histidine codons to the 3′ cloning primer. A Factor Xa recognition site permits cleavage of the pMAL tag from 24P4C12. The pMAL-c2X and pMAL-p2X vectors are optimized to express the recombinant protein in the cytoplasm or periplasm respectively. Periplasm expression enhances folding of proteins with disulfide bonds.
C. Yeast Constructs:
pESC Constructs: To express 24P4C12 in the yeast species Saccharomyces cerevisiae for generation of recombinant protein and functional studies, all or parts of the 24P4C12 cDNA protein coding sequence are cloned into the pESC family of vectors each of which contain 1 of 4 selectable markers, HIS3, TRP1, LEU2, and URA3 (Stratagene, La Jolla, Calif.). These vectors allow controlled expression from the same plasmid of up to 2 different genes or cloned sequences containing either Flag™ or Myc epitope tags in the same yeast cell. This system is useful to confirm protein-protein interactions of 24P4C12. In addition, expression in yeast yields similar post-translational modifications, such as glycosylations and phosphorylations that are found when expressed in eukaryotic cells.
pESP Constructs: To express 24P4C12 in the yeast species Saccharomyces pombe, all or parts of the 24P4C12 cDNA protein coding sequence are cloned into the pESP family of vectors. These vectors allow controlled high level of expression of a 24P4C12 protein sequence that is fused at either the amino terminus or at the carboxyl terminus to GST which aids purification of the recombinant protein. A Flag™ epitope tag allows detection of the recombinant protein with anti-Flag™ antibody.
A. Mammalian Constructs:
To express recombinant 24P4C12 in eukaryotic cells, the full or partial length 24P4C12 cDNA sequences can be cloned into any one of a variety of expression vectors known in the art. One or more of the following regions of 24P4C12 are expressed in these constructs, amino acids 1 to 710, or any 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more contiguous amino acids from 24P4C12 v.1 through v.6; amino acids 1 to 598, or any 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more contiguous amino acids from 24P4C12 v.7, amino acids 1 to 722, or any 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more contiguous amino acids from 24P4C12 v.8, amino acids 1 to 712, or any 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more contiguous amino acids from 24P4C12 v.9, variants, or analogs thereof.
The constructs can be transfected into any one of a wide variety of mammalian cells such as 293T cells. Transfected 293T cell lysates can be probed with the anti-24P4C12 polyclonal serum, described herein.
pcDNA3.1/MycHis Constructs: To express 24P4C12 in mammalian cells, a 24P4C12 ORF, or portions thereof, of 24P4C12 with a consensus Kozak translation initiation site was cloned into pcDNA3.1/MycHis Version A (Invitrogen, Carlsbad, Calif.). Protein expression is driven from the cytomegalovirus (CMV) promoter. The recombinant proteins have the myc epitope and 6X His epitope fused to the carboxyl-terminus. The pcDNA3.1/MycHis vector also contains the bovine growth hormone (BGH) polyadenylation signal and transcription termination sequence to enhance mRNA stability, along with the SV40 origin for episomal replication and simple vector rescue in cell lines expressing the large T antigen. The Neomycin resistance gene can be used, as it allows for selection of mammalian cells expressing the protein and the ampicillin resistance gene and ColE1 origin permits selection and maintenance of the plasmid in E. coli.
pcDNA4/HisMax Constructs: To express 24P4C12 in mammalian cells, a 24P4C12 ORF, or portions thereof, of 24P4C12 are cloned into pcDNA4/HisMax Version A (Invitrogen, Carlsbad, Calif.). Protein expression is driven from the cytomegalovirus (CMV) promoter and the SP16 translational enhancer. The recombinant protein has Xpress™ and six histidine (6X His) epitopes fused to the amino-terminus. The pcDNA4/HisMax vector also contains the bovine growth hormone (BGH) polyadenylation signal and transcription termination sequence to enhance mRNA stability along with the SV40 origin for episomal replication and simple vector rescue in cell lines expressing the large T antigen. The Zeocin resistance gene allows for selection of mammalian cells expressing the protein and the ampicillin resistance gene and ColE1 origin permits selection and maintenance of the plasmid in E. coli.
pcDNA3.1/CT-GFP-TOPO Construct: To express 24P4C12 in mammalian cells and to allow detection of the recombinant proteins using fluorescence, a 24P4C12 ORF, or portions thereof, with a consensus Kozak translation initiation site are cloned into pcDNA3.1/CT-GFP-TOPO (Invitrogen, CA). Protein expression is driven from the cytomegalovirus (CMV) promoter. The recombinant proteins have the Green Fluorescent Protein (GFP) fused to the carboxyl-terminus facilitating non-invasive, in vivo detection and cell biology studies. The pcDNA3.1CT-GFP-TOPO vector also contains the bovine growth hormone (BGH) polyadenylation signal and transcription termination sequence to enhance mRNA stability along with the SV40 origin for episomal replication and simple vector rescue in cell lines expressing the large T antigen. The Neomycin resistance gene allows for selection of mammalian cells that express the protein and the ampicillin resistance gene and ColE1 origin permits selection and maintenance of the plasmid in E. coli. Additional constructs with an amino-terminal GFP fusion are made in pcDNA3.1/NT-GFP-TOPO spanning the entire length of a 24P4C12 protein.
pTag5: A 24P4C12 ORF, or portions thereof, were cloned into pTag-5. This vector is similar to pAPtag but without the alkaline phosphatase fusion. This construct generates 24P4C12 protein with an amino-terminal IgGκ signal sequence and myc and 6X His epitope tags at the carboxyl-terminus that facilitate detection and affinity purification. The resulting recombinant 24P4C12 protein were optimized for secretion into the media of transfected mammalian cells, and is used as immunogen or ligand to identify proteins such as ligands or receptors that interact with the 24P4C12 proteins. Protein expression is driven from the CMV promoter. The Zeocin resistance gene present in the vector allows for selection of mammalian cells expressing the protein, and the ampicillin resistance gene permits selection of the plasmid in E. coli.
PAPtag: A 24P4C12 ORF, or portions thereof, is cloned into pAPtag-5 (GenHunter Corp. Nashville, Tenn.). This construct generates an alkaline phosphatase fusion at the carboxyl-terminus of a 24P4C12 protein while fusing the IgGK signal sequence to the amino-terminus. Constructs are also generated in which alkaline phosphatase with an amino-terminal IgGK signal sequence is fused to the amino-terminus of a 24P4C12 protein. The resulting recombinant 24P4C12 proteins are optimized for secretion into the media of transfected mammalian cells and can be used to identify proteins such as ligands or receptors that interact with 24P4C12 proteins. Protein expression is driven from the CMV promoter and the recombinant proteins also contain myc and 6X His epitopes fused at the carboxyl-terminus that facilitates detection and purification. The Zeocin resistance gene present in the vector allows for selection of mammalian cells expressing the recombinant protein and the ampicillin resistance gene permits selection of the plasmid in E. coli.
PsecFc: A 24P4C12 ORF, or portions thereof, is also cloned into psecFc. The psecFc vector was assembled by cloning the human immunoglobulin GI (IgG) Fc (hinge, CH2, CH3 regions) into pSecTag2 (Invitrogen, California). This construct generates an IgG1 Fc fusion at the carboxyl-terminus of the 24P4C12 proteins, while fusing the IgGK signal sequence to N-terminus. 24P4C12 fusions utilizing the murine IgG1 Fc region are also used. The resulting recombinant 24P4C12 proteins are optimized for secretion into the media of transfected mammalian cells, and can be used as immunogens or to identify proteins such as ligands or receptors that interact with 24P4C12 protein. Protein expression is driven from the CMV promoter. The hygromycin resistance gene present in the vector allows for selection of mammalian cells that express the recombinant protein, and the ampicillin resistance gene permits selection of the plasmid in E. coli.
pSRα Constructs: To generate mammalian cell lines that express 24P4C12 constitutively, 24P4C12 ORF, or portions thereof, of 24P4C12 were cloned into pSRα constructs. Amphotropic and ecotropic retroviruses were generated by transfection of pSRα constructs into the 293T-10A1 packaging line or co-transfection of pSRα and a helper plasmid (containing deleted packaging sequences) into the 293 cells, respectively. The retrovirus is used to infect a variety of mammalian cell lines, resulting in the integration of the cloned gene, 24P4C12, into the host cell-lines. Protein expression is driven from a long terminal repeat (LTR). The Neomycin resistance gene present in the vector allows for selection of mammalian cells that express the protein, and the ampicillin resistance gene and ColE1 origin permit selection and maintenance of the plasmid in E. coli. The retroviral vectors can thereafter be used for infection and generation of various cell lines using, for example, PC3, NIH 3T3, TsuPr1, 293 or rat-1 cells.
Additional pSRα constructs are made that fuse an epitope tag such as the FLAG™ tag to the carboxyl-terminus of 24P4C12 sequences to allow detection using anti-Flag antibodies. For example, the FLAG™ sequence 5′ gat tac aag gat gac gac gat aag 3′ (SEQ ID NO: 172) is added to cloning primer at the 3′ end of the ORF. Additional pSRα constructs are made to produce both amino-terminal and carboxyl-terminal GFP and myc/6X His fusion proteins of the full-length 24P4C12 proteins.
Additional Viral Vectors: Additional constructs are made for viral-mediated delivery and expression of 24P4C12. High virus titer leading to high level expression of 24P4C12 is achieved in viral delivery systems such as adenoviral vectors and herpes amplicon vectors. A 24P4C12 coding sequences or fragments thereof are amplified by PCR and subcloned into the AdEasy shuttle vector (Stratagene). Recombination and virus packaging are performed according to the manufacturer's instructions to generate adenoviral vectors. Alternatively, 24P4C12 coding sequences or fragments thereof are cloned into the HSV-1 vector (Imgenex) to generate herpes viral vectors. The viral vectors are thereafter used for infection of various cell lines such as PC3, NIH 3T3, 293 or rat-1 cells.
Regulated Expression Systems: To control expression of 24P4C12 in mammalian cells, coding sequences of 24P4C12, or portions thereof, are cloned into regulated mammalian expression systems such as the T-Rex System (Invitrogen), the GeneSwitch System (Invitrogen) and the tightly-regulated Ecdysone System (Sratagene). These systems allow the study of the temporal and concentration dependent effects of recombinant 24P4C12. These vectors are thereafter used to control expression of 24P4C12 in various cell lines such as PC3, NIH 3T3, 293 or rat-1 cells.
B. Baculovirus Expression Systems
To generate recombinant 24P4C12 proteins in a baculovirus expression system, 24P4C12 ORF, or portions thereof, are cloned into the baculovirus transfer vector pBlueBac 4.5 (Invitrogen), which provides a His-tag at the N-terminus. Specifically, pBlueBac-24P4C12 is co-transfected with helper plasmid pBac-N-Blue (Invitrogen) into SF9 (Spodoptera frugiperda) insect cells to generate recombinant baculovirus (see Invitrogen instruction manual for details). Baculovirus is then collected from cell supernatant and purified by plaque assay.
Recombinant 24P4C12 protein is then generated by infection of HighFive insect cells (Invitrogen) with purified baculovirus. Recombinant 24P4C12 protein can be detected using anti-24P4C12 or anti-His-tag antibody. 24P4C12 protein can be purified and used in various cell-based assays or as immunogen to generate polyclonal and monoclonal antibodies specific for 24P4C12.
24P4C12 antigenicity profiles, Hydrophilicity, (Hopp T. P., Woods K. R., 1981. Proc. Natl. Acad. Sci. U.S.A. 78:3824-3828); Hydropathicity, (Kyte J., Doolittle R. F., 1982. J. Mol. Biol. 157:105-132); Percentage Accessible Residues (Janin J., 1979 Nature 277:491-492); Average Flexibility, (Bhaskaran R., and Ponnuswamy P. K., 1988. Int. J. Pept. Protein Res. 32:242-255); Beta-turn (Deleage, G., Roux B. 1987 Protein Engineering 1:289-294); and optionally others available in the art, such as on the ProtScale website, were used to identify antigenic regions of the 24P4C12 protein. Each of the above amino acid profiles of 24P4C12 were generated using the following ProtScale parameters for analysis: 1) A window size of 9; 2) 100% weight of the window edges compared to the window center; and, 3) amino acid profile values normalized to lie between 0 and 1.
Hydrophilicity, Hydropathicity and Percentage Accessible Residues profiles were used to determine stretches of hydrophilic amino acids (i.e., values greater than 0.5 on the Hydrophilicity and Percentage Accessible Residues profile, and values less than 0.5 on the Hydropathicity profile). Such regions are likely to be exposed to the aqueous environment, be present on the surface of the protein, and thus available for immune recognition, such as by antibodies.
Average Flexibility and Beta-turn profiles determine stretches of amino acids (i.e., values greater than 0.5 on the Beta-turn profile and the Average Flexibility profile) that are not constrained in secondary structures such as beta sheets and alpha helices. Such regions are also more likely to be exposed on the protein and thus accessible to immune recognition, such as by antibodies.
Antigenic sequences of the 24P4C12 protein and of the variant proteins indicated, e.g., by the profiles are used to prepare immunogens, either peptides or nucleic acids that encode them, to generate therapeutic and diagnostic anti-24P4C12 antibodies. The immunogen can be any 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, 50 or more than 50 contiguous amino acids, or the corresponding nucleic acids that encode them, from the 24P4C12 protein variants listed in
All immunogens of the invention, peptide or nucleic acid, can be embodied in human unit dose form, or comprised by a composition that includes a pharmaceutical excipient compatible with human physiology.
Analysis for the potential presence of transmembrane domains in 24P4C12 variants were carried out using a variety of transmembrane prediction algorithms accessed from the ExPasy molecular biology server.
Polyclonal antibodies can be raised in a mammal, for example, by one or more injections of an immunizing agent and, if desired, an adjuvant. Typically, the immunizing agent and/or adjuvant will be injected in the mammal by multiple subcutaneous or intraperitoneal injections. In addition to immunizing with the full length 24P4C12 protein, computer algorithms are employed in design of immunogens that, based on amino acid sequence analysis contain characteristics of being antigenic and available for recognition by the immune system of the immunized host (see the Example entitled “Antigenicity Profiles and Secondary Structure”). Such regions would be predicted to be hydrophilic, flexible, in beta-turn conformations, and be exposed on the surface of the protein.
For example, 24P4C12 recombinant bacterial fusion proteins or peptides containing hydrophilic, flexible, beta-turn regions of 24P4C12 variant proteins are used as antigens to generate polyclonal antibodies in New Zealand White rabbits. For example, such regions include, but are not limited to, amino acids 1-34, amino acids 118-135, amino acids 194-224, amino acids 280-290, and amino acids 690-710, of 24P4C12 variants 1. It is useful to conjugate the immunizing agent to a protein known to be immunogenic in the mammal being immunized. Examples of such immunogenic proteins include, but are not limited to, keyhole limpet hemocyanin (KLH), serum albumin, bovine thyroglobulin, and soybean trypsin inhibitor. In one embodiment, a peptide encoding amino acids 1-14 of 24P4C12 variant 1 was conjugated to KLH and used to immunize a rabbit. This antiserum exhibited a high titer to the peptide (>10,000) and recognized 24P4C12 in transfected 293T cells by Western blot and flow cytometry (
In one embodiment, a GST-fusion protein encoding amino acids 379-453, encompassing the third predicted extracellular loop of variant 1, is produced, purified, and used as immunogen. Other recombinant bacterial fusion proteins that may be employed include maltose binding protein, LacZ, thioredoxin, NusA, or an immunoglobulin constant region (see the section entitled “Production of 24P4C12 in Prokaryotic Systems” and Current Protocols In Molecular Biology, Volume 2, Unit 16, Frederick M. Ausubul et al. eds., 1995; Linsley, P. S., Brady, W., Urnes, M., Grosmaire, L., Damle, N., and Ledbetter, L. (1991) J. Exp. Med. 174, 561-566).
In addition to bacterial derived fusion proteins, mammalian expressed protein antigens are also used. These antigens are expressed from mammalian expression vectors such as the Tag5 and Fc-fusion vectors (see the Example entitled “Production of Recombinant 24P4C12 in Eukaryotic Systems”), and retains post-translational modifications such as glycosylations found in native protein. Each recombinant protein is then purified by metal chelate chromatography from tissue culture supernatants and/or lysates of 293T cells stably expressing the recombinant vector. The purified Tag5 24P4C12 protein is then used as immunogen.
During the immunization protocol, it is useful to mix or emulsify the antigen in adjuvants that enhance the immune response of the host animal. Examples of adjuvants include, but are not limited to, complete Freund's adjuvant (CFA) and MPL-TDM adjuvant (monophosphoryl Lipid A, synthetic trehalose dicorynomycolate).
In a typical protocol, rabbits are initially immunized subcutaneously with up to 200 μg, typically 100-200 μg, of fusion protein or peptide conjugated to KLH mixed in complete Freund's adjuvant (CFA). Rabbits are then injected subcutaneously every two weeks with up to 200 μg, typically 100-200 μg, of the immunogen in incomplete Freund's adjuvant (IFA). Test bleeds are taken approximately 7-10 days following each immunization and used to monitor the titer of the antiserum by ELISA.
Anti-serum from rabbits immunized with 24P4C12 variant fusion proteins, such as GST and MBP fusion proteins, are purified by depletion of antibodies reactive to the fusion partner sequence by passage over an affinity column containing the fusion partner either alone or in the context of an irrelevant fusion protein. For example, antiserum derived from a GST-24P4C12 fusion protein encoding amino acids 379-453 of variant 1 is first purified by passage over a column of GST protein covalently coupled to AffiGel matrix (BioRad, Hercules, Calif.). The antiserum is then affinity purified by passage over a column composed of a MBP-fusion protein also encoding amino acids 379-453 covalently coupled to Affigel matrix. The serum is then further purified by protein G affinity chromatography to isolate the IgG fraction. Sera from other His-tagged antigens and peptide immunized rabbits as well as fusion partner depleted sera are affinity purified by passage over a column matrix composed of the original protein immunogen or free peptide.
In one embodiment, therapeutic Monoclonal Antibodies (“MAbs”) to 24P4C12 and 24P4C12 variants comprise those that react with epitopes specific for each protein or specific to sequences in common between the variants that would bind, internalize, disrupt or modulate the biological function of 24P4C12 or 24P4C12 variants, for example, those that would disrupt the interaction with ligands, substrates, and binding partners. Immunogens for generation of such MAbs include those designed to encode or contain the extracellular domains or the entire 24P4C12 protein sequence, regions predicted to contain functional motifs, and regions of the 24P4C12 protein variants predicted to be antigenic from computer analysis of the amino acid sequence. Immunogens include peptides and recombinant proteins such as tag5-24P4C12, a purified mammalian cell derived His tagged protein. In addition, cells engineered to express high levels of 24P4C12, such as RAT1-24P4C12 or 300.19-24P4C12, are used to immunize mice.
To generate MAbs to 24P4C12, mice are first immunized with 1-50 μg of protein immunogen or between 106 and 107 24P4C12-expressing cells mixed in a suitable adjuvant. Examples of suitable adjuvants for immunizations are TiterMax (Sigma) and alum gel. Following an initial injection, mice are immunized twice a week until they are ready to be selected for fusions. When mice are ready for fusions (see below), B cells are harvested either from lymph nodes or spleen. Harvested B cells are mixed with a standard mouse derived fusion partner and cells are fused using electro-cell fusion (ECF).
In the course of the immunizations test bleeds are taken to monitor the titer and specificity of the immune response. In most cases, once appropriate reactivity and specificity are obtained as determined by ELISA, Western blotting, immunoprecipitation, fluorescence microscopy or flow cytometric analyses, fusion and hybridoma generation are then carried out using electrocell fusion (ECF).
In one embodiment, the invention provides for monoclonal antibodies designated: Ha5-1(5)1, Ha5-1(5)2.1, Ha5-3(1,4)2.1, Ha5-3(1,4)7.1, Ha5-3(3,5)37.1, Ha5-4(2,5)13.1, Ha5-4(2,5)34.1, Ha5-7acd4.1, Ha5-7acd20.1.1, Ha5-7be31.1, Ha5-7acd10.1, Ha5-7acd13.1, Ha5-7acd19.1, Ha5-7be37.1, Ha5-7acd16.1, Ha5-7acd7.1.1, Ha5-7be20.1, Ha5-7acd5.1.1, Ha5-7be34.1, Ha5-7acd3.1, Ha5-7acd2.1, Ha5-8ac4.1, Ha5-4(2,5)31.1, Ha5-11a1.1.1, Ha5-11b1.1, and Ha5-7be7.1.
MAbs to 24P4C12 were generated using XenoMouse Technology® (Amgem Fremont) wherein the murine heavy and kappa light chain loci have been inactivated and a majority of the human heavy and kappa light chain immunoglobulin loci have been inserted. MAbs designated Ha5-3(1,4)2.1, Ha5-3(1,4)7.1, Ha5-3(3,5)37.1, Ha5-7acd4.1, Ha5-7acd20.1.1, Ha5-7be31.1, Ha5-7acd10.1, Ha5-7acd13.1, Ha5-7acd19.1, Ha5-7be37.1, Ha5-7acd16.1, Ha5-7acd7.1.1, Ha5-7be20.1, Ha5-7acd5.1.1, Ha5-7be34.1, Ha5-7acd3.1, Ha5-7acd2.1, Ha5-8ac4.1, Ha5-4(2,5)31.1, Ha5-11a1.1.1, Ha5-11b1.1, and Ha5-7be7.1 were generated from immunization of human γ1 producing XenoMice with RAT(E)-24P4C12 cells. MAbs designated Ha5-1(5)1 and Ha5-1(5)2.1 were generated from immunization of human γ2 producing XenoMice with B300.19-24P4C12 cells. MAbs designated Ha5-4(2,5)13.1 and Ha5-4(2,5)34.1 were generated from immunization with human γ1 producing XenoMice with purified tag5-24P4C12 (aa 59-227).
The 24P4C12 MAbs Ha5-1(5)1, Ha5-1(5)2.1, Ha5-3(1,4)2.1, Ha5-3(1,4)7.1, Ha5-3(3,5)37.1, Ha5-7acd4.1, Ha5-7acd20.1.1, Ha5-7be31.1, Ha5-7acd10.1, Ha5-7acd13.1, Ha5-7acd19.1, Ha5-7be37.1, Ha5-7acd16.1, Ha5-7acd7.1.1, Ha5-7be20.1, Ha5-7acd5.1.1, Ha5-7be34.1, Ha5-7acd3.1, Ha5-7acd2.1, Ha5-8ac4.1, and Ha5-7be7.1 specifically bind to recombinant 24P4C12 expressing cells (PC3-24P4C12) and multiple cancer cell lines expressing 24P4C12 (
The antibodies designated Ha5-1(5)1, Ha5-1(5)2.1, Ha5-3(1,4)7.1, Ha5-7acd10.1, Ha5-7acd16.1, and Ha5-11b1.1 were sent (via Federal Express) to the American Type Culture Collection (ATCC), P.O. Box 1549, Manassas, Va. 20108 on 8 Aug. 2007 and assigned Accession numbers PTA-8598, PTA-8602, PTA-8597, PTA-8601, PTA-8600, PTA-8599, respectively.
DNA coding sequences for 24P4C12 MAbs Ha5-1(5)1, Ha5-1(5)2.1, Ha5-3(1,4)2.1, Ha5-3(1,4)7.1, Ha5-3(3,5)37.1, Ha5-4(2,5)13.1, Ha5-4(2,5)34.1, Ha5-7acd4.1, Ha5-7acd20.1.1, Ha5-7be31.1, Ha5-7acd10.1, Ha5-7acd13.1, Ha5-7acd19.1, Ha5-7be37.1, Ha5-7acd16.1, Ha5-7acd7.1.1, Ha5-7be20.1, Ha5-7acd5.1.1, Ha5-7be34.1, Ha5-7acd3.1, Ha5-7acd2.1, Ha5-8ac4.1, Ha5-4(2,5)31.1, Ha5-11a1.1.1, Ha5-11b1.1, and Ha5-7be7.1 were determined after isolating mRNA from the respective hybridoma cells with Trizol reagent (Life Technologies, Gibco BRL).
Anti-24P4C12 heavy and light chain variable nucleic acid sequences were sequenced from the hybridoma cells using the following protocol. Anti-24P4C12 secreting hybridoma cells were lysed with Trizol reagent (Life Technologies, Gibco BRL). Total RNA was purified and quantified. First strand cDNAs was generated from total RNA with oligo (dT)12-18 priming using the Gibco-BRL Superscript Preamplification system. First strand cDNA was amplified using human immunoglobulin variable heavy chain primers, and human immunoglobulin variable light chain primers. PCR products were sequenced and the variable heavy and light chain regions determined.
The nucleic acid and amino acid sequences of the variable heavy and light chain regions are listed in
Antibodies generated using the procedures set forth in the example entitled “Generation of 24P4C12 Monoclonal Antibodies (MAbs)” were screened, identified, and characterized using a combination of assays including ELISA, FACS, affinity ranking by Surface Plasmon Resonance (BIAcore) (“SPR”), epitope grouping, affinity to recombinant 24P4C12, and 24P4C12 expressed on the cell surface.
24P4C12 Human MAb Screening by FACS.
Primary hybridoma screening for MAbs to 24P4C12 is performed by FACS analysis. The protocol is as follows: 50 μl/well of hybridoma supernatant (neat) or purified antibodies (in serial dilutions) are added to 96-well FACS plates and mixed with 24P4C12-expressing cells (endogenous or recombinant, 50,000 cells/well). The mixture is incubated at 4° C. for two hours. At the end of incubation, the cells are washed with FACS Buffer and incubated with 100 μl of detection antibody (anti-hIgG-PE) for 45 minutes at 4° C. At the end of incubation, the cells are washed with FACS Buffer, fixed with Formaldehyde and analyzed using FACScan. Data are analyzed using CellQuest Pro software.
Positive hybridomas identified from primary screens are transferred to 24-well plates and supernatants collected for confirmatory screens.
B. 24P4C12 Human MAb Screening by ELISA.
24P4C12 MAbs are screened by ELISA to determine antibody isotype. The protocol used is as follows, ELISA plates are coated with Tag5-24P4C12-ECD or anti-hIgG antibody. Several sets of testing antibodies are added on the plates and incubated for 1 hour. After washing the plates to wash out unbound antibodies, bound antibodies are detected by the following HRP conjugated detection antibodies: anti-hIgG1, anti-hIgG2, anti-hIgK, and anti-hIgL.
C. 24P4C12 Human MAb Screening by SPR.
SPR allows identification and real time characterization of the kinetics and affinity of protein-protein interactions and therefore is a useful technique in the selection and characterization of MAbs to target antigens of interest (i.e. 24P4C12). SPR analysis is employed to screen and characterize hybridoma supernatants and purified MAbs to 24P4C12. Hybridoma screening for MAbs to 24P4C12 by SPR biosensor (BIAcore 3000) are performed as follows: 50 μl/well of hybridoma supernatant (neat) diluted to 1.5-2 μg/ml with the running buffer (HBS-P, 10 ug/ml BSA) are added to 96-well plates (BIAcore) and MAbs (20 μl) are captured on goat-anti-human Fcγ pAbs covalently immobilized on the surface of the CM5 sensor chip. Three (3) MAbs containing hybridoma supernatants are tested per run (cycle) on channels 2, 3 and 4 of the flow cell, where channel 1 is reserved as reference for non-specific binding. Prior to measuring antigen binding to captured MAbs in each individual channel, 60 μl of running buffer is injected over the chip surface at the flowrate of 20 μl/min to serve as reference for drift in captured MAb baseline. Sixty microliters (60 μl) of the purified recombinant 161P2F10B at 150 nM is then injected over the chip surface at the same flowrate of 20 μl/min to measure antigen binding. Each cycle of antigen binding to MAbs are followed by surface regeneration with injection of 100 mM phosphoric acid (for 1 min) to strip the surface of any captured MAb.
Data analysis is performed using BiaEvaluation 4.1 and CLAMP software (Myszka and Morton, 1998). After subtracting the references and normalizing the response to the level of captured MAb, data is fit globally using a 1:1 binding model.
The affinities are calculated from the association and dissociation rate constants. As is apparent to one of ordinary skill in the art, slow dissociation rates generally indicate higher overall affinity for MAbs. The preliminary affinity data and dissociation rates are used as a basis of the selection criteria for therapeutic MAbs to 24P4C12.
D. Epitope Grouping by FACS
24P4C12 antibodies were grouped according to epitope by evaluating their binding pattern using Rat1-24P4C12 cells. In brief, a small amount of each of the antibodies were biotinylated; then each of the biotinylated antibodies were incubated with Rat1-24P4C12 in the presence of excess (100×) amount of non-biotinylated antibodies at 4° C. for 1 hour. One of ordinary skill in the art will understand that during the incubation, an excess amount of antibodies will compete with biotinylated antibodies if they bind to the same epitope. At the end of incubation, cells were washed and incubated with Streptavidin-PE for 45 min at 4° C. After washing off the unbound streptavidin-PE, the cells were analyzed using FACS. MFI values were obtained using CellQuest Pro software and were used for data analysis. As described, twenty-eight (28) 24P4C12 MAbs were epitope grouped using Rat1-24P4C12 cells. The results show the antibodies that have the same binding pattern bind to the same epitope among the antibodies and that there are 17 epitope groups within the antibodies tested. The listing of the 24P4C12 MAbs and there respective epitope group are shown in Table VI.
E. Affinity Determination by FACS
A panel of 24 human 24P4C12 MAbs were tested for their binding affinity to 24P4C12 on LNCaP cells. The affinity to LNCaP cells was determined by FACS using saturation equilibrium binding assay. The 24P4C12 MAbs were serially diluted in FACS Buffer and incubated with LNCaP cells with final concentration of 160 to 0.003 nM at 4° C. for 16 hours. At the end of incubation, the cells were washed with FACS Buffer and incubated with 100 ul of detection antibody (anti-hIgG-PE) for 45 minutes at 4° C., the cells were then washed with FACS Buffer, fixed with 2% Formaldehyde and analyzed using FACScan. FACS data were analyzed using CellQuest Pro software to acquire histogram and Mean Fluoresces Intensity (MFI) values of each point. The MFI values were used to calculate the binding affinity using non-linear regression using Prism4 software (Graphpad Software Inc. San Diego Calif.). A summary of affinity values of twenty-four (24) antibodies are set forth in Table VI.
F. Affinity Determination by SPR
Panels of purified anti-human 24P4C12 MAbs are tested for their binding affinity to the purified recombinant 24P4C12 by SPR. Briefly, each purified human MAb is captured onto a CM5 sensor chip surface. On average approximately 150 RUs of each MAb is captured in every cycle. A series of 5-6 dilutions of recombinant 24P4C12 ranging from 1 nM to 100 nM is injected over such surface to generate binding curves (sensograms) that are globally fit to a 1:1 interaction model using CLAMP software (Myszka and Morton, 1998). The affinity of several 24P4C12 MAbs, expressed as KD, defined by dissociation rate constant and association rate constant using the equation KD=kdiss/kassoc is determined.
G. Cross Reactivity with Cynnomolgous Monkey 24P4C12
24P4C12 MAbs are screened and characterized for their ability to react with 24P4C12 of monkey origin. This property is useful to understand the expression of 24P4C12 on tissues from different monkey species for toxicological purposes. The cynomolgous monkey 24P4C12 gene was cloned and sequenced. The homology to human 24P4C12 is 96.8% (
ADCC (Antibody-Dependent Cellular Cytotoxicity) is an immune mediated lytic attack on cells bound with an antibody targeted to a specific cell surface antigen. Immune cells recognize the Fc portion of the antibody through binding to Fcã receptors on the surface of leukocytes, monocytes, and NK cells triggering a lytic attack that result in cell death. Briefly, Caki cells engineered to express the target antigen 24P4C12 are incubated in vitro with 51chromium for 1 hr. After washing with fresh medium, the labeled cells are incubated with 2.5 mg/ml human MAbs directed to 24P4C12 and freshly isolated peripheral blood mono nuclear cells at different effector to target cell ratios (E:T Ratio). After 4 hours at 37 C, the cells are gently centrifuged and the supernatant containing 51Cr released from the dead cells is counted in a Beta counter.
The results demonstrate that antibody dependent cell killing increases when the effector to target (E:T) cell ratio increases. The specificity of the assay is determined by showing that an irrelevant IgG1 Control MAb and incubation of target cells and effector cells in the absence of antibody (Cells+PBMCs) do not cause cell killing.
Antibodies to 24P4C12 mediate saporin dependent killing in PC3-24P4C12 cells. Briefly, PC3-24P4C12 or PC3-Neo cells (500 cells/well) were seeded into a 96 well plate on day 1. The following day an equal volume of medium containing 2× concentration of the indicated primary antibody together with a 2 fold excess of anti-human (Hu-Sap) or anti-goat (Gt-Sap) polyclonal antibody conjugated with saporin toxin (Advanced Targeting Systems, San Diego, Calif.) was added to each well. The cells were allowed to incubate for 5 days at 37 degrees C. At the end of the incubation period, Alamar Blue was added to each well and incubation continued for an additional 4 hours. The fluorescence of each well was determined in a plate reader using an excitation wavelength of 530 nm and an emission wavelength of 590 nm.
The results show that 24P4C12 antibodies HA5-1(5)1.1, HA5-1(5)2.1 and HA5-acd16.1 mediated saporin dependent cytotoxicity in PC3 cells expressing 24P4C12 but not in PC3 cells infected with the Neo gene alone. To further demonstrate specificity, the same primary 24P4C12 antibodies were incubated with a 2 fold excess of saporin conjugated goat polyclonal antibody. These results indicate that drugs or cytotoxic proteins can selectively be delivered to cells expressing 24P4C12 using an appropriate anti-24P4C12 MAb.
Generation of F(Ab′)2 fragments of MAbs is useful to study the effects of MAb molecules that retain their bivalent antigen binding site but lack the immune effector Fc domain in in vitro and in vivo therapeutic models. Generally, the protocol is as follows, 20 mgs of MAb in 20 mM sodium acetate buffer pH 4.5 is incubated with and without immobilized pepsin (Pierce. Rockford Ill.) for the indicated times. Intact MAb and digested Fc fragments are removed by protein A chromatography. The reagent can be used to treat animals bearing 24P4C12 expressing tumors. The anti-tumor activity observed with this antibody fragment can distinguish intrinsic biologic activity from activity mediated by immune dependent mechanisms.
To express 24P4C12 MAbs recombinantly in transfected cells, 24P4C12 MAb variable heavy and light chain sequences are cloned upstream of the human heavy chain IgG1 and light chain Igκ constant regions respectively. The complete 24P4C12 MAb human heavy chain and light chain cassettes are cloned downstream of the CMV promoter/enhancer in a cloning vector. A polyadenylation site is included downstream of the MAb coding sequence. The recombinant 24P4C12 MAb expressing constructs are transfected into 293T, Cos and CHO cells. The 24P4C12 MAbs secreted from recombinant cells are evaluated for binding to cell surface 24P4C12.
The effect of the 24P4C12 protein on tumor cell growth is evaluated in vivo by evaluating tumor development and growth of cells expressing or lacking 24P4C12. For example, SCID mice are injected subcutaneously on each flank with 1×106 of colon cancer cell lines containing tkNeo empty vector or 24P4C12. At least two strategies may be used: (1) Constitutive 24P4C12 expression under regulation of a promoter such as a constitutive promoter obtained from the genomes of viruses such as polyoma virus, fowlpox virus (UK 2,211,504 published 5 Jul. 1989), adenovirus (such as Adenovirus 2), bovine papilloma virus, avian sarcoma virus, cytomegalovirus, a retrovirus, hepatitis-B virus and Simian Virus 40 (SV40), or from heterologous mammalian promoters, e.g., the actin promoter or an immunoglobulin promoter, provided such promoters are compatible with the host cell systems, and (2) Regulated expression under control of an inducible vector system, such as ecdysone, tetracycline, etc., provided such promoters are compatible with the host cell systems. Tumor volume is then monitored by caliper measurement at the appearance of palpable tumors and followed over time to determine if 24P4C12-expressing cells grow at a faster rate and whether tumors produced by 24P4C12-expressing cells demonstrate characteristics of altered aggressiveness (e.g. enhanced metastasis, vascularization, reduced responsiveness to chemotherapeutic drugs).
Additionally, mice can be implanted with 1×105 of the same cells orthotopically to determine if 24P4C12 has an effect on local growth in the colon, and whether 24P4C12 affects the ability of the cells to metastasize (Miki T et al, Oncol Res. 2001; 12:209; Fu X et al, Int J Cancer. 1991, 49:938). The effect of 24P4C12 on tumor formation and growth may be assessed by injecting colon tumor cells intratibially.
The assay is also useful to determine the 24P4C12 inhibitory effect of candidate therapeutic compositions, such as for example, 24P4C12 intrabodies, 24P4C12 antisense molecules, and ribozymes.
The significant expression of 24P4C12 on the cell surface of tumor tissues, together with its restrictive expression in normal tissues makes 24P4C12 a good target for antibody therapy. Similarly, 24P4C12 is a target for T cell-based immunotherapy. Thus, the therapeutic efficacy of 24P4C12 MAbs in human cancer xenograft mouse models is evaluated by using multiple cancer cell lines such as PC3-24P4C12, LNCaP, LAPC9, 22RV1, OVCaR-5, HT29, Calu-1, and CF-PAC.
Antibody efficacy on tumor growth and metastasis formation is studied, e.g., in a mouse orthotopic cancer xenograft model. The antibodies can be unconjugated, as discussed in this Example, or can be conjugated to a therapeutic modality, as appreciated in the art. 24P4C12 MAbs inhibit formation of colon cancer xenografts. 24P4C12 MAbs also retard the growth of established orthotopic tumors and prolonged survival of tumor-bearing mice. These results indicate the utility of 24P4C12 MAbs in the treatment of local and advanced stages of colon cancer and those cancers set forth in Table I.
Administration of the 24P4C12 MAbs led to retardation of established orthotopic tumor growth and inhibition of metastasis to distant sites, resulting in a significant prolongation in the survival of tumor-bearing mice. These studies indicate that 24P4C12 is an attractive target for immunotherapy and demonstrate the therapeutic potential of 24P4C12 MAbs for the treatment of local and metastatic colon cancer. This example demonstrates that unconjugated 24P4C12 MAbs are effective to inhibit the growth of human colon tumor xenografts grown in SCID mice; accordingly a combination of such efficacious MAbs is also effective.
Tumor Inhibition Using Multiple 24P4C12 MAbs
Materials and Methods
24P4C12 Monoclonal Antibodies:
Monoclonal antibodies were raised against 24P4C12 as described in the Example entitled “Generation of 24P4C12 Monoclonal Antibodies (MAbs).” The MAbs are characterized by ELISA, Western blot, FACS, and immunoprecipitation for their capacity to bind 24P4C12. Epitope mapping data for the 24P4C12 MAbs, as determined by ELISA and Western analysis, recognize epitopes on the 24P4C12 protein. Immunohistochemical analysis of normal and cancer tissues and cells with these antibodies is performed.
The MAbs are purified from ascites or hybridoma tissue culture supernatants by Protein-G or Protein-A Sepharose chromatography, dialyzed against PBS, filter sterilized, and stored at −20° C. Protein determinations are performed by a Bradford assay (Bio-Rad, Hercules, Calif.). A therapeutic MAb or a cocktail comprising a mixture of individual MAbs is prepared and used for the treatment of mice receiving subcutaneous or orthotopic injections of UG-K3 and RXF-393 tumor xenografts.
Cell Lines and Xenografts
The cancer cell lines PC3-24P4C12, LNCaP, LAPC9, 22RV1, OVCaR-5, HT29, Calu-1, and CF-PAC are maintained in RPMI and DMEM respectively, supplemented with L-glutamine and 10% FBS.
The xenograft is passaged in 6-8-week-old male ICR-severe combined immunodeficient (SCID) mice (Taconic Farms) by s.c. trocar implant (Craft, N., et al., Nat. Med. 1999, 5:280). Single-cell suspensions of tumor cells are prepared as described in Craft, et al. Other cell lines are used as well.
Xenograft Mouse Models.
Subcutaneous (s.c.) tumors are generated by injection of 1×106 cancer cells mixed at a 1:1 dilution with Matrigel (Collaborative Research) in the right flank of male SCID mice. To test antibody efficacy on tumor formation, i.e. antibody injections are started on the same day as tumor-cell injections. As a control, mice are injected with either purified mouse IgG (ICN) or PBS; or a purified MAb that recognizes an irrelevant antigen not expressed in human cells. In preliminary studies, no difference is found between mouse IgG or PBS on tumor growth. Tumor sizes are determined by caliper measurements, and the tumor volume is calculated as length×width×height. Mice with subcutaneous tumors greater than 1.5 cm in diameter are sacrificed.
Orthotopic injections are performed under anesthesia by using ketamine/xylazine. To monitor tumor growth, mice are palpated. The mice are segregated into groups for the appropriate treatments, with 24P4C12 MAbs or control MAbs being injected i.p.
24P4C12 MAbs Inhibit Growth of 24P4C12-Expressing Xenograft Tumors
The effect of 24P4C12 MAbs on tumor formation is tested by using orthotopic models. As compared with the s.c. tumor model, the orthotopic model, which requires injection of tumor cells directly in the mouse, results in a local tumor growth, development of metastasis in distal sites, deterioration of mouse health, and subsequent death. These features make the orthotopic model more representative of human disease progression and allowed us to follow the therapeutic effect of 24P4C12 MAbs on clinically relevant end points.
Accordingly, tumor cells are injected into the mouse, and 2 days later, the mice are segregated into two groups and treated with either: a) 250-1000 μg, of 24P4C12 MAb, or b) control antibody three times per week for two to five weeks.
A major advantage of the orthotopic cancer models is the ability to study the development of metastases. Formation of metastasis in mice bearing established orthotopic tumors is studies by IHC analysis on tissue sections.
Another advantage of xenograft cancer models is the ability to study neovascularization and angiogenesis. Tumor growth is partly dependent on new blood vessel development. Although the capillary system and developing blood network is of host origin, the initiation and architecture of the neovasculature is regulated by the xenograft tumor (Davidoff et al., Clin Cancer Res. (2001) 7:2870; Solesvik et al., Eur J Cancer Clin Oncol. (1984) 20:1295). The effect of antibody and small molecule on neovascularization is studied in accordance with procedures known in the art, such as by IHC analysis of tumor tissues and their surrounding microenvironment.
Mice bearing established orthotopic tumors are administered injections of either 24P4C12 MAb or control antibody over a 4-week period. Mice in both groups are allowed to establish a high tumor burden, to ensure a high frequency of metastasis formation in mouse lungs. Mice then are killed and their bladders, livers, bone and lungs are analyzed for the presence of tumor cells by IHC analysis. These studies demonstrate a broad anti-tumor efficacy of anti-24P4C12 antibodies on initiation and progression of cancer in xenograft mouse models. Anti-24P4C12 antibodies inhibit tumor formation of tumors as well as retarding the growth of already established tumors and prolong the survival of treated mice. Moreover, 24P4C12 MAbs demonstrate a dramatic inhibitory effect on the spread of local tumor to distal sites, even in the presence of a large tumor burden. Thus, 24P4C12 MAbs are efficacious on major clinically relevant end points (tumor growth), prolongation of survival, and health.
The results of these experiments show that 24P4C12 MAbs can be used for therapeutic and diagnostic purposes to treat and manage cancers set forth in Table I.
Anti-24P4C12 monoclonal antibodies are safely and effectively used for diagnostic, prophylactic, prognostic and/or therapeutic purposes in humans. Western blot and immunohistochemical analysis of cancer tissues and cancer xenografts with anti-24P4C12 MAb show strong extensive staining in carcinoma but significantly lower or undetectable levels in normal tissues. Detection of 24P4C12 in carcinoma and in metastatic disease demonstrates the usefulness of the MAb as a diagnostic and/or prognostic indicator. Anti-24P4C12 antibodies are therefore used in diagnostic applications such as immunohistochemistry of kidney biopsy specimens to detect cancer from suspect patients.
As determined by flow cytometry, anti-24P4C12 MAb specifically binds to carcinoma cells. Thus, anti-24P4C12 antibodies are used in diagnostic whole body imaging applications, such as radioimmunoscintigraphy and radioimmunotherapy, (see, e.g., Potamianos S., et. al. Anticancer Res 20(2A):925-948 (2000)) for the detection of localized and metastatic cancers that exhibit expression of 24P4C12. Shedding or release of an extracellular domain of 24P4C12 into the extracellular milieu, such as that seen for alkaline phosphodiesterase B10 (Meerson, N. R., Hepatology 27:563-568 (1998)), allows diagnostic detection of 24P4C12 by anti-24P4C12 antibodies in serum and/or urine samples from suspect patients.
Anti-24P4C12 antibodies that specifically bind 24P4C12 are used in therapeutic applications for the treatment of cancers that express 24P4C12. Anti-24P4C12 antibodies are used as an unconjugated modality and as conjugated form in which the antibodies are attached to one of various therapeutic or imaging modalities well known in the art, such as a prodrugs, enzymes, toxins, or radioisotopes. In preclinical studies, unconjugated and conjugated anti-24P4C12 antibodies are tested for efficacy of tumor prevention and growth inhibition in the SCID mouse cancer xenograft models, e.g., colon cancer models, (see, e.g., the Example entitled “24P4C12 Monoclonal Antibody-mediated Inhibition of Tumors In Vivo”). Either conjugated and unconjugated anti-24P4C12 antibodies are used as a therapeutic modality in human clinical trials either alone or in combination with other treatments as described in following Examples.
Antibodies are used in accordance with the present invention which recognize an epitope on 24P4C12, and are used in the treatment of certain tumors, preferably those listed in Table I. In connection with each of these indications, three clinical approaches are successfully pursued.
I.) Adjunctive therapy: In adjunctive therapy, patients are treated with 24P4C12 MAbs (either naked or conjugated to an agent) in combination with a chemotherapeutic or anti-neoplastic agent and/or radiation therapy or a combination thereof. Primary cancer targets, such as those listed in Table I, are treated under standard protocols by the addition of 24P4C12 MAbs to standard first and second line therapy. Protocol designs address effectiveness as assessed by the following examples, including but not limited to, reduction in tumor mass of primary or metastatic lesions, increased progression free survival, overall survival, improvement of patients health, disease stabilization, as well as the ability to reduce usual doses of standard chemotherapy and other biologic agents. These dosage reductions allow additional and/or prolonged therapy by reducing dose-related toxicity of the chemotherapeutic or biologic agent. 24P4C12 MAbs are utilized in several adjunctive clinical trials in combination with the chemotherapeutic or anti-neoplastic agents.
II.) Monotherapy: In connection with the use of the 24P4C12 MAbs (either naked or conjugated) in monotherapy of tumors, the antibodies are administered to patients without a chemotherapeutic or anti-neoplastic agent. In one embodiment, monotherapy is conducted clinically in end-stage cancer patients with extensive metastatic disease. Protocol designs address effectiveness as assessed by the following examples, including but not limited to, reduction in tumor mass of primary or metastatic lesions, increased progression free survival, overall survival, improvement of patients health, disease stabilization, as well as the ability to reduce usual doses of standard chemotherapy and other biologic agents.
III.) Imaging Agent: Through binding a radionuclide (e.g., iodine or yttrium (I131, Y90) to 24P4C12 MAbs, the radiolabeled antibodies are utilized as a diagnostic and/or imaging agent. In such a role, the labeled antibodies localize to both solid tumors, as well as, metastatic lesions of cells expressing 24P4C12. In connection with the use of the 24P4C12 MAbs as imaging agents, the antibodies are used as an adjunct to surgical treatment of solid tumors, as both a pre-surgical screen as well as a post-operative follow-up to determine what tumor remains and/or returns. In one embodiment, a (111In)-24P4C12 antibody is used as an imaging agent in a Phase I human clinical trial in patients having a carcinoma that expresses 24P4C12 (by analogy see, e.g., Divgi et al. J. Natl. Cancer Inst. 83:97-104 (1991)). Patients are followed with standard anterior and posterior gamma camera. The results indicate that primary lesions and metastatic lesions are identified.
Dosage regimens may be adjusted to provide the optimum desired response. For example, a single bolus may be administered, several divided doses may be administered over time or the dose may be proportionally reduced or increased as indicated by the exigencies of the therapeutic situation. It is especially advantageous to formulate parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein refers to physically discrete units suited as unitary dosages for the mammalian subjects to be treated; each unit containing a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms of the invention are dictated by and directly dependent on (a) the unique characteristics of the antibody and the particular therapeutic or prophylactic effect to be achieved, and (b) the limitations inherent in the art of compounding such an active compound for the treatment of sensitivity in individuals.
An exemplary, non limiting range for a therapeutically effective amount of an antibody administered in combination according to the invention is at least 1 mg/kg, at least 5 mg/kg, at least 10 mg/kg, more than 10 mg/kg, or at least 15 mg/kg, for example 1-21 mg/kg, or for example 5-21 mg/kg, or for example 5-18 mg/kg, or for example 10-18 mg/kg, or for example 15 mg/kg. The high dose embodiment of the invention relates to a dosage of more than 10 mg/kg. It is to be noted that dosage values may vary with the type and severity of the condition to be alleviated, and may include single or multiple doses. It is to be further understood that for any particular subject, specific dosage regimens should be adjusted over time according to the individual need and the professional judgment of the person administering or supervising the administration of the compositions, and that dosage ranges set forth herein are exemplary only and are not intended to limit the scope or practice of the claimed composition.
Clinical Development Plan (CDP)
The CDP follows and develops treatments of 24P4C12 MAbs in connection with adjunctive therapy, monotherapy, and/or as an imaging agent. Trials initially demonstrate safety and thereafter confirm efficacy in repeat doses. Trials are open label comparing standard chemotherapy with standard therapy plus 24P4C12 MAbs. As will be appreciated, one non-limiting criteria that can be utilized in connection with enrollment of patients is 24P4C12 expression levels in their tumors as determined by biopsy.
As with any protein or antibody infusion-based therapeutic, safety concerns are related primarily to (i) cytokine release syndrome, i.e., hypotension, fever, shaking, chills; (ii) the development of an immunogenic response to the material (i.e., development of human antibodies by the patient to the antibody therapeutic, or HAHA response); and, (iii) toxicity to normal cells that express 24P4C12. Standard tests and follow-up are utilized to monitor each of these safety concerns. 24P4C12 MAbs are found to be safe upon human administration.
24P4C12, a 10-transmembrane domain protein, is a member of the choline transporter-like (CTL) family of multi-transmembrane proteins and is member 4 of the family (CTL4). This family also has been recently named by the HUGO Gene Nomenclature Committee as Solute Carrier family 44 (SLC44) and 24P4C12 as SLC44A4 (solute carrier family 44, member 4). This family was originally identified with the cloning and functional analysis of CTL1. This ubiquitously expressed protein, also known as CDw92, was shown to transport choline in a sodium-independent manner. 24P4C12 is 46% homologous to CTL1 at the amino acid level, thus it is inferred that 24P4C12 also functions as a macromolecule or ion transporter. For reference, the membrane topology of 24P4C12 and CTL1 respectively is shown in
Potential extracellular asparagine linked glycosylation residues are shown in purple, potential extracellular cysteines used in disulfide bonds are shown in green. Charged amino acids within the transmembrane domains are also shown. Basic amino acids residues, arginine, histidine, and lysine are shown in blue and the acidic residue glutamic acid is shown in red. These charged residues are likely to be important for the transport function of the protein through mediating proper tertiary structure of the helices and/or movement of the macromolecule or ion through the channel or pore structure formed by the protein. Although CTL1 has been reported to function as a choline transporter, due to the differences in the transmembrane topology and the number and spacing of the charged amino acids in 24P4C12 compared to CTL1, it is probable that 24P4C12 mediates the transport macromolecules or ions other than choline.
24P4C12 is expressed in the apical membranes of several glandular secretory epithelia, including prostate, colon, small intestine, lung bronchus, pancreas, and the carcinomas that arise from these tissues. 24P4C12 has prominent expression in apical membrane of normal prostate. The major biological function of the prostate is to create and secrete prostatic fluid. It is conceivable that 24P4C12, acting as a transporter, regulates the composition of prostatic fluid. In one embodiment, the substrate of 24P4C12 is present in prostatic fluid. Substrates of 24P4C12 that are present in prostatic fluid are listed in Table VII. Potassium concentration is elevated in prostatic fluid (30-50 mM) compared to serum (3-4 mM), thus in another embodiment 24P4C12 transports potassium or utilizes potassium as a counterion in the transport of another macromolecule.
To confirm 24P4C12 transport activity, MDCK-24P4C12 cells demonstrate a decrease in chloromethylfluorescein diacetate (CMFDA) fluorescence, a pH sensitive fluorescent dye, compared to control neo cells when exposed to high extracellular potassium (K+) concentrations. This result indicates a drop in intracellular pH, suggesting that 24P4C12 transport activity does involve K+ and/or H+ ions. (
Additionally, prostatic fluid is slightly acidic, exhibiting a pH range of 6.4-6.8, thus 24P4C12 may also regulate the pH homeostasis of prostatic fluid. MDCK-24P4C12 cells exhibit a marked decrease in CMFDA fluorescence compared to control neo cells when exposed to media acidified with sodium propionate. These results suggest 24P4C12 may regulate the intracellular pH homeostasis of cells when exposed to a low pH environment. (
In another embodiment, 24P4C12 transport activity involves regulating intracellular pH in response to pH changes in the extracellular environment. Many of the macromolecules and ions present in prostatic fluid are also present in the fluids bathing or secreted by apical epithelium of other organs expressing 24P4C12. Such organs include but are not limited to lung bronchus, colon, small intestine, pancreas, and kidney. The transport activity of 24P4C12 may regulate the homeostasis of the fluids and secretions in these organs. Other substrates of 24P4C12 transporter activity based on the composition of fluids present in organs comprising the digestive tract and lung bronchi are listed in Table VIII.
During the oncogenic process of normal tissues, tumor cells may adapt or upregulate transport activities that provide beneficial nutrients, ions, macromolecules, or signaling pathways that promote tumor growth and metastasis. 24P4C12 transport activity may provide such benefits to the tumor. Therefore 24P4C12 MAbs that block or downregulate 24P4C12 transport activity would provide a therapeutic benefit by inhibiting tumor growth or mediating cell death. In one embodiment, 24P4C12 MAbs bind to 24P4C12 protein and sterically block the channel or pore that mediates the transport activity. In another embodiment, 24P4C12 MAbs bind to 24P4C12 causing conformational changes that disrupt the transport activity. In a further embodiment, 24P4C12 MAbs mediate capping, internalization, and downregulation of 24P4C12 from the cell surface.
Such capping and internalization removes 24P4C12 transport activity from the cell surface thereby providing an inhibitory effect on the tumor cell.
Expression of 24P4C12 protein by immunohistochemistry was tested in tumor specimens of pancreatic and ovarian cancer. Briefly, formalin fixed, paraffin wax-embedded tissues were cut into 4 micron sections and mounted on glass slides. The sections were de-waxed, rehydrated and treated with trypsin solution (0.05% trypsin (ICN, Aurora, Ohio) in 0.05% calcium chloride, with pH adjusted to 7.8) at 37° C. for 10 minutes. Sections were then treated with 3% hydrogen peroxide solution to inactivate endogenous peroxidase activity. Serum-free protein block (Dako, Carpenteria, Calif.) was used to inhibit non-specific binding prior to incubation with monoclonal mouse anti-24P4C12 antibody. Subsequently, the sections were treated with the Super Sensitive™ Polymer-horseradish peroxidase (HRP) Detection System which consists of an incubation in Super Enhancer™ reagent followed by an incubation with polymer-HRP secondary antibody conjugate (BioGenex, San Ramon, Calif.). The sections were then developed using the DAB kit (BioGenex, San Ramon, Calif.), nuclei were stained using hematoxylin, and analyzed by bright field microscopy. The cells which contain antigen immunoreactive with the 24P4C12 antibody stain brown.
The results show expression of 24P4C12 in the tumor cells of human ovarian cancer tissue and pancreatic cancer tissue. These results indicate that 24P4C12 is expressed in human cancers and that antibodies directed to this antigen are useful for diagnostic and therapeutic purposes. (
Throughout this application, various website data content, publications, patent applications and patents are referenced. (Websites are referenced by their Uniform Resource Locator, or URL, addresses on the World Wide Web.) The disclosures of each of these references are hereby incorporated by reference herein in their entireties.
The present invention is not to be limited in scope by the embodiments disclosed herein, which are intended as single illustrations of individual aspects of the invention, and any that are functionally equivalent are within the scope of the invention. Various modifications to the models and methods of the invention, in addition to those described herein, will become apparent to those skilled in the art from the foregoing description and teachings, and are similarly intended to fall within the scope of the invention. Such modifications or other embodiments can be practiced without departing from the true scope and spirit of the invention.